28. Below is a relative frequency bar chart of the number of children in American households. The horizontal axis is the number of children (o, 1, 2, 3, or 4) and the vertical axis is the fraction of households with that many children. 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 1 2 3 4 a) Describe the shape of this graph: is it uniform, symmetric, skewed right, or skewed left? b) Since probabilities are just relative frequencies, we can fill in the following probability table. All you have to do is read off the chart above. You may need a straight edge to help. One box has been filled in for you to show the idea. 1 3 4 P(x) 0.24 c) Check to make sure that you've accounted for 100% of the data by adding up the second row – you should get 1.00
28. Below is a relative frequency bar chart of the number of children in American households. The horizontal axis is the number of children (o, 1, 2, 3, or 4) and the vertical axis is the fraction of households with that many children. 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 1 2 3 4 a) Describe the shape of this graph: is it uniform, symmetric, skewed right, or skewed left? b) Since probabilities are just relative frequencies, we can fill in the following probability table. All you have to do is read off the chart above. You may need a straight edge to help. One box has been filled in for you to show the idea. 1 3 4 P(x) 0.24 c) Check to make sure that you've accounted for 100% of the data by adding up the second row – you should get 1.00
MATLAB: An Introduction with Applications
6th Edition
ISBN:9781119256830
Author:Amos Gilat
Publisher:Amos Gilat
Chapter1: Starting With Matlab
Section: Chapter Questions
Problem 1P
Related questions
Question
can you answer 28a,b,c
![28. Below is a relative frequency bar chart of the number of children in American households. The
horizontal axis is the number of children (0, 1, 2, 3, or 4) and the vertical axis is the fraction of households
with that many children.
0.4
ili.
0.35
0.3
0.25
0.2
0.15
0.1
0.05
1
2
4
a) Describe the shape of this graph: is it uniform, symmetric, skewed right, or skewed left?
b) Since probabilities are just relative frequencies, we can fill in the following probability table. All you
have to do is read off the chart above. You may need a straight edge to help. One box has been filled in
for you to show the idea.
1
2
3
4
P(x)
0.24
c) Check to make sure that you’ve accounted for 100% of the data by adding up the second row – you
should get 1.00
d) Verify that the mean of this distribution is u = 1.1 The formula is µ = E[xP(x)], which means that
you should multiply each column of the table, x times P(x), then add all the results. Since you've been
given the answer, the key here is to show your work.](/v2/_next/image?url=https%3A%2F%2Fcontent.bartleby.com%2Fqna-images%2Fquestion%2F8b729196-85f9-4b0e-a4b2-d6475729d74c%2F456d715e-d614-4562-87a8-024b216fe608%2Fgn5u8nl_processed.jpeg&w=3840&q=75)
Transcribed Image Text:28. Below is a relative frequency bar chart of the number of children in American households. The
horizontal axis is the number of children (0, 1, 2, 3, or 4) and the vertical axis is the fraction of households
with that many children.
0.4
ili.
0.35
0.3
0.25
0.2
0.15
0.1
0.05
1
2
4
a) Describe the shape of this graph: is it uniform, symmetric, skewed right, or skewed left?
b) Since probabilities are just relative frequencies, we can fill in the following probability table. All you
have to do is read off the chart above. You may need a straight edge to help. One box has been filled in
for you to show the idea.
1
2
3
4
P(x)
0.24
c) Check to make sure that you’ve accounted for 100% of the data by adding up the second row – you
should get 1.00
d) Verify that the mean of this distribution is u = 1.1 The formula is µ = E[xP(x)], which means that
you should multiply each column of the table, x times P(x), then add all the results. Since you've been
given the answer, the key here is to show your work.
![When doing statistics, usually we do not have access to the population data represented in that bar graph.
Instead, we might try to use a survey to estimate the mean number of children in an American household.
Suppose that a survey is taken with a sample size of 36. The results are summarized as follows:
Sample mean is x = 1.3
Sample standard deviation is s = 0.7
e) Find the margin of error E for this survey, with 99% confidence. Be sure to look up the correct
formula. If you are unfamiliar with E, it's the number after the “+/-" in Professor Avedikian's notes. Here
is a useful portion of the chart for Student's t-distribution.
Area to the right of t
0.05
0.025
0.005
t-score, df= 35
1.690
2.030 2.724
t-score, df= 36
1.688
2.028
2.719
t-score, df= 37
1.687
2.026
2.715
Confidence level
90%
95%
99%
f) Fill in the blanks in the following statement with the appropriate numbers (rounded off).
"Based on the results of our survey, we are
% confident that the population mean µ is
between
and
g) Simple yes or no: did this survey "get it right"? In other words, is the true value u = 1.1 within the
confidence interval?
h) If you were able to spend more time and money in order to improve the survey, what should you do?
What is the best way to either increase the confidence or decrease the margin of error?](/v2/_next/image?url=https%3A%2F%2Fcontent.bartleby.com%2Fqna-images%2Fquestion%2F8b729196-85f9-4b0e-a4b2-d6475729d74c%2F456d715e-d614-4562-87a8-024b216fe608%2Ffzmkwk_processed.jpeg&w=3840&q=75)
Transcribed Image Text:When doing statistics, usually we do not have access to the population data represented in that bar graph.
Instead, we might try to use a survey to estimate the mean number of children in an American household.
Suppose that a survey is taken with a sample size of 36. The results are summarized as follows:
Sample mean is x = 1.3
Sample standard deviation is s = 0.7
e) Find the margin of error E for this survey, with 99% confidence. Be sure to look up the correct
formula. If you are unfamiliar with E, it's the number after the “+/-" in Professor Avedikian's notes. Here
is a useful portion of the chart for Student's t-distribution.
Area to the right of t
0.05
0.025
0.005
t-score, df= 35
1.690
2.030 2.724
t-score, df= 36
1.688
2.028
2.719
t-score, df= 37
1.687
2.026
2.715
Confidence level
90%
95%
99%
f) Fill in the blanks in the following statement with the appropriate numbers (rounded off).
"Based on the results of our survey, we are
% confident that the population mean µ is
between
and
g) Simple yes or no: did this survey "get it right"? In other words, is the true value u = 1.1 within the
confidence interval?
h) If you were able to spend more time and money in order to improve the survey, what should you do?
What is the best way to either increase the confidence or decrease the margin of error?
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