week 8 Test
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School
American Military University *
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Course
302
Subject
Mathematics
Date
Feb 20, 2024
Type
docx
Pages
19
Uploaded by bradymcdede
Attempt Score
19 / 20 - 95 %
Overall Grade (Highest Attempt)
19 / 20 - 95 %
stion 1
1 / 1 p
A college prep school advertises that their students are more prepared to succeed in college than other schools. To verify this, they categorize GPA's into 4 groups and look up the proportion of students at a state college in each category. They find that 7% have a 0-0.99, 21% have a 1-1.99, 37% have a 2-2.99, and 35% have a 3-4.00 in GPA.
They then take a random sample of 200 of their graduates at the state college and find that 19 has a 0-0.99, 28 have a 1-1.99, 82 have a 2-2.99, and 71 have a 3-4.00.
Can they conclude that the grades of their graduates are distributed differently than the general population at the school? Test at the 0.05 level of significance.
Hypotheses:
H
0
: There is ______ between the general population and the college prep students in GPA.
H
1
: There is ______ between the general population and the college prep students in GPA.
Select the best fit choices that fit in the two blank spaces above.
no difference, a difference
a difference, no difference
no difference, no difference
a difference, a difference
Question 2
1 / 1
point
Pamplona, Spain is the home of the festival of San Fermin – The Running of the Bulls. The town is in festival mode for a week and a half every year at the beginning of July. There is a running joke in the city, that Pamplona has a baby boom every
April – 9 months after San Fermin. To test this claim, a resident takes a random sample of 300 birthdays from native residents and finds the following
observed counts
:
January
25
February
25
March
27
April
26
May
21
June
26
July
22
August
27
September 21
October
26
November 28
December 26
At the 0.05 level of significance, can it be concluded that births in Pamplona are not equally distributed throughout the 12 months of the year?
Enter the
p
-value - round to 4 decimal places. Make sure you put a 0 in front of the decimal.
P-value =___
Answer:
0.9960
Hide question 2 feedback
Expected counts will be all the same. 300*(1/12) = 25. The 12 months are either equally distributed or they are not.
Use Excel to find the p-value you have the Observed and Expected Counts you can use
=CHISQ.TEST( Highlight Observed Counts, Highlight Expected Counts) = 0.9960
n 3
1 The permanent residence of adults aged 18-25 in the U.S. was examined in a survey from the year 2000. The survey revealed that 27% of these adults lived alone, 32% lived with a roommate(s), and 41% lived with their parents/guardians. In 2008, during an economic recession in the country, another such survey of 1600 people revealed that 398 lived alone, 488 lived with a roommate(s), and 714 lived with their parents. Is there a significant difference in where young adults lived in 2000 versus 2008? Test with a Goodness of Fit test at
α=0.05
.
Enter the observed and expected counts for each category in the table below. Round to whole numbers.
Alone
Roommates
Parents/Guardians
Observed Counts
___
___
___
Expected Counts
___
___
___
___
Answer for blank # 1:
398
(16.67 %)
Answer for blank # 2:
488
(16.67 %)
Answer for blank # 3:
714
(16.67 %)
Answer for blank # 4:
432
(16.67 %)
Answer for blank # 5:
512
(16.67 %)
Answer for blank # 6:
656
(16.67 %)
Hide question 3 feedback
The observed counts are given to you, 398, 488, and 714
Calculate expected counts 1600*.27, 1600*.32 and 1600*.41
n 4
1 A college professor is curious if the location of seat in class affects grades in the class. They are teaching in a lecture hall with 240 students. The lecture hall has 10 rows, so they split the rows into 5 sections – Rows 1-2, Rows 3-4, Rows 5-6, Rows 7-8, and Rows 9-10. At the end of the course, they determine
the top 25% of grades in the class, and if the location of the seat makes no difference, they would expect that these top 25% of students would be equally
dispersed throughout the classroom. Their observations are recorded below. Run a Goodness of Fit test to determine whether or not location has an impact on the grade. Let α=0.05.
Hypotheses:
H
0
: Location in the classroom
__________
impact final grade.
H
1
: Location in the classroom _________ impact final grade.
Select the best fit choices that fit in the two blank spaces above.
does not, does
does, does not
does, does
does not, does not
Question 5
1 / 1
point
A company that develops over-the-counter medicines is working on a new product that is meant to shorten the length of sore throats. To test their product for effectiveness, they take a random sample of 110 people and record how long it took for their symptoms to completely
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disappear. The results are in the table below. The company knows that on average (without medication) it takes a sore throat 6 days or less to heal 42% of the time, 7-9 days 31% of the time, 10-12 days 16% of the time, and 13 days or more 11% of the time. Can it be concluded at the 0.01 level of significance that the patients who took the medicine healed at a different rate than these percentages?
Enter the expected count for each category in the table below. Round to 1 decimal place.
6 days or less
7-9 days
10-12 days
13 or more days
Duration of Sore
Throat
49
40
12
9
Expected Counts
___
___
___
___
Answer for blank # 1:
46.2
(25 %)
Answer for blank # 2:
34.1
(25 %)
Answer for blank # 3:
17.6
(25 %)
Answer for blank # 4:
12.1
(25 %)
Hide question 5 feedback
Expected Counts = 110*.42
110*.31
110*.16
110*.11
n 6
0 Students at a high school are asked to evaluate their experience in the class at the end of each school year. The courses are evaluated on a 1-4 scale – with 4 being the best experience possible. In the History Department, the courses
typically are evaluated at 10% 1's, 15% 2's, 34% 3's, and 41%
4's.
Mr. Goodman sets a goal to outscore these numbers. At the end of the year he takes a random sample of his evaluations and finds 10 1's, 13 2's, 48 3's, and 52 4's. At the 0.05 level of
significance, can Mr. Goodman claim that his evaluations are significantly different than the History Department's?
Enter the
p
-value - round to 4 decimal places. Make sure you put a 0 in front of the decimal.
p-value=___
___
Answer:
0.2005
(0.3913)
Hide question 6 feedback
1's
2's
3's
4's
Observed Counts
10
13
48
52
Expected Counts
123 *.10 = 12.3
123*.15 = 18.45
123*.34 = 41.82
123*.41 = 50.43
Use Excel to find the p-value
=CHISQ.TEST(Highlight Observed, Highlight Expected)
n 7
1 The manager of a coffee shop wants to know if his customers' drink preferences have changed
in the past year. He knows that last year the preferences followed the following proportions – 34% Americano, 21% Cappuccino, 14% Espresso, 11% Latte, 10% Macchiato, 10% Other. In a random sample of 450 customers, he finds that 115 ordered Americanos, 88 ordered Cappuccinos, 69 ordered Espressos, 59 ordered Lattes, 44 ordered Macchiatos, and the rest ordered something in the Other category. Run a Goodness of Fit test to determine whether or not drink preferences have changed at his coffee shop. Use a 0.05 level of significance.
Hypotheses:
H
0
: There is
_______
in drink preference this year.
H
1
: There is
_______
in drink preference this year.
Select the best fit choices that fit in the two blank spaces above.
no difference, a difference
a difference, no difference
no difference, no difference
a difference, a difference
Question 8
1 / 1
point
A college professor is curious if the location of a seat in class affects grades in the class. They are teaching in a lecture hall with 240 students. The lecture hall has 10 rows, so they split the rows into 5 sections – Rows 1-2, Rows 3-4, Rows 5-6, Rows
7-8, and Rows 9-10. At the end of the course, they determine the top 25% of grades in the class, and if the location of the seat makes no difference, they would expect that these top 25% of students would be equally dispersed throughout the classroom. Their observations are recorded below.
Run a Goodness of Fit test to determine whether or not location has an impact on the grade. Let α=0.05. After running
a Goodness of Fit test, does the professor have evidence to conclude that location in the classroom has an impact on final grade and what is the p-value?
Rows 1-2
Rows 3-4
Rows 5-6
Rows 7-8
Rows 9-10
# in Top 25%
14
8
13
10
15
Expected
Counts
12
12
12
12
12
no, the p-value = 0.413907
yes, the p-value = 0.586093
no, the p-value = 0.58609
yes, the p-value = 0.413907
Hide question 8 feedback
Use Excel to find the p-value you have the Observed and Expected Counts you can use
=CHISQ.TEST( Highlight Observed Counts, Highlight
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Expected Counts) = 0.586093
0.586093 > .05, Do Not Reject Ho. No, this is not significant.
n 9
1 A company operates three machines during three shifts each day. From production records, the data in the table below were collected.
At the .05 level of significance test to determine if the number
of breakdowns is independent of the shift.
Machine
Shift
A
B
C
1
46
11
13
2
37
10
11
3
20
15
16
Yes, you can reject the claim that the number of breakdowns is independent of the shift because the p-value = 0.0423
Yes, you can reject the claim that the number of breakdowns is independent of the shift because the p-value = 0.9577
No, you cannot reject the claim that the number of breakdowns is independent of the shift because the p-value = 0.0423
No, you cannot reject the claim that the number of breakdowns is independent of the shift because the p-value = 0.9577
Hide question 9 feedback
We are running a Chi-Square Test for Independence. Copy and Paste the table into Excel. You are given the Observed Counts in the table. We need to calculate the Expected Counts Then sum up the rows and column. You need to find the probability of the row and then multiple it by the column total.
Machine
Shift
A
B
C
Sum
1
46
11
13
70
2
37
10
11
58
3
20
15
16
51
Sum
103
36
40
179
Shift
A
B
C
1
=103*(70/179
)
=36*(70/179) =40*(70/179)
2
=103*(58/179
)
=36*(58/179) =40*(58/179)
3
=103*(51/179
)
=36*(51/179) =40*(51/179)
Now that we calculated the Expected Count we can use Excel to find the p-value. Use =CHISQ.TEST(highlight actual counts, highlight expected counts) = 0.0423
0.0423 < .05, Reject Ho. You can reject the claim that the number of breakdowns is independent of the shift.
n 10
1 The data presented in the table below resulted from an experiment in which seeds of 4 different types were planted and the number of seeds that germinated within 4 weeks after
planting was recorded for each seed type.
At the .05 level of significance, is the proportion of seeds that germinate dependent on the seed type?
Seed Type
Observed Frequencies
Germinated
Failed to
Germinate
1
39
9
2
54
34
3
88
63
4
57
42
No, the proportion of seeds that germinate are not dependent on the seed type because the p-value = 0.0132.
No, the proportion of seeds that germinate are not dependent on the seed type because the p-value = 0.0265.
Yes, the proportion of seeds that germinate dependent on the seed type because the p-value = 0.0265.
Yes, the proportion of seeds that germinate dependent on the seed type because the p-value = 0.0132.
Hide question 10 feedback
We are running a Chi-Square Test for Independence. Copy and Paste the table into Excel. You are given the Observed Counts in the table. We need to calculate the Expected Counts Then sum up the rows and column. You need to find the probability of the row and then multiple it by the column total.
Observed Frequencies
Germinated
Failed to Germinate
Sum
1
39
9
48
2
54
34
88
3
88
63
151
4
57
42
99
Sum
238
148
386
Germinated
Failed to Germinate
1
=238*(48/386)
=148*(48/386)
2
=238*(88/386)
=148*(88/386)
3
=238*(151/386)
=148*(151/386)
4
=238*(99/386)
=148*(99/386)
Now that we calculated the Expected Count we can use Excel to find the p-value.
Use =CHISQ.TEST(highlight actual counts, highlight expected counts) = 0.0265
0.0265 < .05, Reject Ho. Yes, the proportion of seeds that germinate dependent on the seed type.
n 11
1 A company operates three machines during three shifts each day. From production records, the data in the table below were collected.
At the .05 level of significance test to determine if the number
of breakdowns is independent of the shift.
Machine
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Shift
A
B
C
1
46
11
13
2
37
10
11
3
20
15
16
What is the Expected Count for Shift = 3 and Machine = C?
15.642
11.397
14.078
10.257
Hide question 11 feedback
We are running a Chi-Square Test for Independence. Copy and Paste the table into Excel. You are given the Observed Counts in the table. We need to calculate the Expected Counts Then sum up the rows and column. You need to find the probability of the row and then multiple it by the column total.
Machine
Shift
A
B
C
Sum
1
46
11
13
70
2
37
10
11
58
3
20
15
16
51
Sum
103
36
40
179
Shift
A
B
C
1
=103*(70/179
)
=36*(70/179) =40*(70/179)
2
=103*(58/179
)
=36*(58/179) =40*(58/179)
3
=103*(51/179
)
=36*(51/179) =40*(51/179)
=40*(51/179) = 11.397
n 12
1
A university changed to a new learning management system during the past school year. The school wants to find out how it's working for the different departments – the results in preference found from a survey are below. Run a test for independence at
α=0.05
.
Prefers Old LMS
Prefers New LMS
No Preference
School of Business
18
29
8
School of Science
41
11
4
School of Liberal Arts
25
20
7
After running an independence test, can it be concluded that preference in learning management system is dependent on department?
No, it cannot be concluded that preference in learning management system is dependent on department because the p-value = 0.0017
No, it cannot be concluded that preference in learning management system is dependent on department because the p-value = 0.00085
Yes, it can be concluded that preference in learning management system is dependent on department because the p-value = 0.00085
Yes, it can be concluded that preference in learning management system is dependent on department because the p-value = 0.0017
Hide question 12 feedback
We are running a Chi-Square Test for Independence. Copy and Paste the table into Excel. You are given the Observed Counts in the table. We need to calculate the Expected Counts. Then sum
up the rows and column. You need to find the probability of the row and then multiple it by the column total.
Prefers Old LMS
Prefers New LMS
No Preference
Sum
School of Business
18
29
8
55
School of Science
41
11
4
56
School of Liberal Arts
25
20
7
52
Sum
84
60
19
163
Prefers Old LMS
Prefers New LMS
No Preference
School of Business
=84*(55/163)
=60*(55/163)
=19*(55/163)
School of Science
=84*(56/163)
=60*(56/163)
=19*(56/163)
School of Liberal Arts
=84*(52/163)
=60*(52/163)
=19*(52/163)
Now that we calculated the Expected Count we can use Excel to find the p-value. Use
=CHISQ.TEST(highlight actual counts, highlight expected counts) = 0.00085
0.00085 < 0.05, Reject Ho. Yes, it can be concluded that preference in learning management system is dependent on department.
n 13
1 The following sample was collected during registration at a large middle school. At the 0.05 level of significance, can it be concluded that level of math is dependent on grade level?
Honors Math
Regular Math
General Math
6
th
Grade
35
47
14
7
th
Grade
37
49
12
8
th
Grade
33
48
19
After running an independence test, can it be concluded that level of math is dependent on grade level?
Yes, it can be concluded that level of math is dependent on grade level, because the p-value
= 0.75413
No, it cannot be concluded that level of math is dependent on grade level, because the p-
value = 0.24587
No, it cannot be concluded that level of math is dependent on grade level, because the p-
value = 0.75413
Yes, it can be concluded that level of math is dependent on grade level, because the p-value
= 0.24587
Hide question 13 feedback
We are running a Chi-Square Test for Independence. Copy and Paste the table into Excel. You are given the Observed Counts in the table. We need to calculate the Expected Counts. Then sum
up the rows and column. You need to find the probability of the row and then multiple it by the column total.
Honors Math
Regular Math
General Math
Sum
6th Grade
35
47
14
96
7th Grade
37
49
12
98
8th Grade
33
48
19
100
Sum
105
144
45
294
Honors Math
Regular Math
General Math
6th =105*(96/294) =144*(96/294) =45*(96/294)
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Grade
7th Grade
=105*(98/294) =144*(98/294) =45*(98/294)
8th Grade
=105*(100/294
)
=144*(100/294
)
=45*(100/294
)
Now that we calculated the Expected Count we can use Excel to find the p-value. Use =CHISQ.TEST(highlight actual counts, highlight expected counts) = 0.75413
0.75413 > .05, Do Not Reject Ho. No, it cannot be concluded that level of math is dependent on grade level.
n 14
1 A university changed to a new learning management system during the past school year. The school wants to find out how it's working for the different departments – the results in preference found from a survey are below. Run a test for independence at
α=0.05
.
Prefers Old LMS
Prefers New LMS
No Preference
School of Business
18
29
8
School of Science
41
11
4
School of Liberal Arts
25
20
7
Hypotheses:
H
0
:
Pass/fail rates are
_______
school.
H
1
:
Pass/fail rates are
_______
school.
Which of the following best fits the blank spaces above?
dependent of, independent on
dependent of, dependent on
independent of; independent on
independent of, dependent on
Question 15
1 / 1
point
The medal count for the 2018 winter Olympics is recorded below. Run an independence test to find out if the medal won is dependent on country. Use
α=0.10
.
Gold
Silver
Bronze
Norway
17
14
11
Germany
16
9
6
Canada
13
9
11
United States
12
10
7
Can it be concluded that medal won is dependent on country?
No, it cannot be concluded that medal won is dependent on country because p = 0.1139.
No, it cannot be concluded that medal won is dependent on country because p = 0.8861.
Yes, it can be concluded that medal won is dependent on country because p = 0.1139.
Yes, it can be concluded that medal won is dependent on country because p = 0.8861.
Hide question 15 feedback
We are running a Chi-Square Test for Independence. Copy and Paste the table into Excel. You are given the Observed Counts in the table. Next you need to sum the rows and columns. Once you have those you need to calculate the Expected Counts. You need to find the probability of the row and then multiple it by the column total.
Gold
Silver
Bronze
Sum
Norway
17
14
11
42
Germany
16
9
6
31
Canada
13
9
11
33
United States
12
10
7
29
Sum
58
42
35
135
Gold
Silver
Bronze
Norway
=58*(42/135)
=42*(42/135)
=35*(42/135)
Germany
=58*(31/135)
=42*(31/135)
=35*(31/135)
Canada
=58*(33/135)
=42*(33/135)
=35*(33/135)
United States
=58*(29/135)
=42*(29/135)
=35*(29/135)
Now that we calculated the Expected Count we can use Excel to find the p-value.
Use =CHISQ.TEST(highlight actual counts, highlight expected counts) = 0.8861
0.8861 > 0.05, Do Not Reject Ho. No, it cannot be concluded that medal won is dependent on country.
n 16
1 An electronics store has 4 branches in a large city. They are curious if sales in any particular department are different depending on location. They take a random sample of 4 purchases throughout the 4 branches – the results are recorded below. Run an independence test for the data below at the 0.05 level of significance.
Appliances
TV
Computers
Cell Phones
Branch 1
56
28
63
24
Branch 2
44
22
55
27
Branch 3
53
17
49
33
Branch 4
51
31
66
29
Enter the
P
-Value - round to 4 decimal places. Make sure you put a 0 in front of the decimal.
___
Answer:
0.6099
Hide question 16 feedback
We are running a Chi-Square Test for Independence. Copy and Paste the table into Excel. You are given the Observed Counts in the table. Next you need to sum the rows and columns. Once you have those you need to calculate the Expected Counts. You need to find the probability of the row and then multiple it by the column total.
Appliances
TV
Computers
Cell Phones
Branch 1
56
28
63
24
Branch 2
44
22
55
27
Branch 3
53
17
49
33
Branch 4
51
31
66
29
Sum
204
98
233
113
Appliances
TV
Computers
Cell Phones
Branch 1
=204*(171/648)
=98*(171/648)
=233*(171/648)
=113*(171/648)
Branch 2
=204*(148/648)
=98*(148/648)
=233*(148/648)
=113*(148/648)
Branch 3
=204*(152/648)
=98*(152/648)
=233*(152/648)
=113*(152/648)
Branch 4
=204*(177/648)
=98*(177/648)
=233*(177/648)
=113*(177/648)
Now that we calculated the Expected Count we can use Excel to find the p-value.
Use =CHISQ.TEST(highlight actual counts, highlight expected counts) = 0.6099
n 17
1 The Test Scores for a Statistics course are given in the Excel below.
The data (X1, X2, X3, X4) are for each student.
X1 = score on exam #1
X2 = score on exam #2
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X3 = score on exam #3
X4 = score on final exam
Your professor wants to know if all tests are created equal.
Looking at the Summary output, which two Exams have the biggest difference in average?
See Attached Excel for Data.
Exam data.xlsx
Exam 1 and the Final
Exam 2 and the Final
Exam 3 and Exam 1
Exam 3 and the Final
Hide question 17 feedback
Run a F-Distribution ANOVA analysis using Excel. Data -> Data Analysis -> the first option is Anova: Single Factor -> Click OK
In the Input Range: Highlight all 4 columns including the top row with the Labels.
Check the box Labels in the First Row and click OK
If done correctly the ANOVA output is
SUMMARY
Groups
Count
Sum
Average
EXAM1
25
1976.00
79.04
EXAM2
25
1987.00
79.48
EXAM3
25
2037.00
81.48
FINAL
25
1755.43
70.22
The Final the lowest average of 70.22%
Exam 3 has the highest average of 81.48%
n 18
1 The following data represent weights (pounds) of a random sample of professional football players on the following teams.
X1 = weights of players for the Dallas Cowboys
X2 = weights of players for the Green Bay Packers
X3 = weights of players for the Denver Broncos
X4 = weights of players for the Miami Dolphins
X5 = weights of players for the San Francisco Forty Niners
You join a Fantasy Football league and you are wondering if weight is a factor in winning Football games.
Looking at the Summary output, which two teams have the biggest difference in weight?
See Attached Excel for Data.
Reference: The Sports Encyclopedia Pro Football
Football Weight data.xlsx
Denver Broncos and Miami Dolphins
San Francisco 49ers and Miami Dolphins
San Francisco 49ers and Green Bay Packers
Denver Broncos and San Francisco 49ers
Hide question 18 feedback
Run a F-Distribution ANOVA analysis using Excel. Data -> Data Analysis -> the first option is Anova: Single Factor -> Click OK
In the Input Range: Highlight all 5 columns including the top row with the Labels.
Check the box Labels in the First Row and click OK.
If done correctly you should get,
SUMMARY
Groups
Count
Sum Average
Variance
Dallas Cowboys Wt.
17 4202
247.18
235.28
Green Bay Packers Wt.
17 4267
251.00
291.63
Denver Broncos Wt.
17 4323
254.29
263.60
Miami Dolphins Wt.
17 4234
249.06
281.06
San Fran. 49ers Wt.
17 4094
240.82
288.53
Denver Broncos have the highest weight sum and average.
San Francisco 49ers have the lowest weight sum and average.
n 19
1 The
F
Statistic from an experiment with
k
= 7 and
n
= 42 is 2.55. At
α
= 0.05, will you reject the null hypothesis?
Yes, because the p-value = 0.0373
No, because the p-value = 0.0373
Yes, because the p-value = 0.0187
Yes, because the p-value = 0.0187
Hide question 19 feedback
Use Excel to find the p-value
df
1
= k - 1 = 7-1 = 6
df
2
= n - k = 42-7 = 35
=F.DIST.RT(2.55,6,35) = 0.0373
0.0373 < .05, Reject Ho, Yes, this is significant.
n 20
1 The
F
Statistic from an experiment with
k
= 3 and
n
= 75 is 2.99. At
α
= 0.05, will you reject the null hypothesis?
Yes, because the p-value = 0.0566
Yes, because the p-value = 0283.
No, because the p-value = 0.0283
No, because the p-value = 0.0566
Hide question 20 feedback
Use Excel to find the p-value
df
1
= k - 1 = 3 -1 = 2
df
2
= n - k = 75 - 3 = 72
=F.DIST.RT(2.99, 2, 72) = 0.0566
0.0566 > 0.05, Do Not Reject Ho, No, this is not significant.
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