Introduction to Probability and Statistics
14th Edition
ISBN: 9781133103752
Author: Mendenhall, William
Publisher: Cengage Learning
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Chapter 8.7, Problem 8.61E
a.
To determine
To find: A 99% confidence interval for the difference
b.
To determine
To check: The difference in population proportions.
c.
To determine
To explain: The difference between the two group is significant or not.
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Calculate the 90% confidence interval for the population mean difference using the data in the attached image. I need to see where I went wrong.
Microsoft Excel snapshot for random sampling: Also note the formula used for the last
column
02
x✓ fx =INDEX(5852:58551, RANK(C2, $C$2:$C$51))
A
B
1
No.
States
2
1
ALABAMA
Rand No.
0.925957526
3
2
ALASKA
0.372999976
4
3
ARIZONA
0.941323044
5
4 ARKANSAS
0.071266381
Random Sample
CALIFORNIA
NORTH CAROLINA
ARKANSAS
WASHINGTON
G7
Microsoft Excel snapshot for systematic sampling:
xfx INDEX(SD52:50551, F7)
A
B
E
F
G
1
No.
States
Rand No. Random Sample
population
50
2
1 ALABAMA
0.5296685 NEW HAMPSHIRE
sample
10
3
2 ALASKA
0.4493186 OKLAHOMA
k
5
4
3 ARIZONA
0.707914 KANSAS
5
4 ARKANSAS 0.4831379 NORTH DAKOTA
6
5 CALIFORNIA 0.7277162 INDIANA
Random Sample
Sample Name
7
6 COLORADO 0.5865002 MISSISSIPPI
8
7:ONNECTICU 0.7640596 ILLINOIS
9
8 DELAWARE 0.5783029 MISSOURI
525
10
15
INDIANA
MARYLAND
COLORADO
Suppose the Internal Revenue Service reported that the mean tax refund for the year 2022 was $3401. Assume the standard deviation is $82.5 and that the amounts refunded follow a normal probability distribution. Solve the following three parts? (For the answer to question 14, 15, and 16, start with making a bell curve. Identify on the bell curve where is mean, X, and area(s) to be determined.
1.What percent of the refunds are more than $3,500?
2. What percent of the refunds are more than $3500 but less than $3579?
3. What percent of the refunds are more than $3325 but less than $3579?
Chapter 8 Solutions
Introduction to Probability and Statistics
Ch. 8.4 - Prob. 8.3ECh. 8.4 - Prob. 8.4ECh. 8.4 - Prob. 8.5ECh. 8.4 - Prob. 8.6ECh. 8.4 - Prob. 8.7ECh. 8.4 - Prob. 8.8ECh. 8.4 - Prob. 8.9ECh. 8.4 - Prob. 8.10ECh. 8.4 - Prob. 8.11ECh. 8.4 - Prob. 8.12E
Ch. 8.4 - Prob. 8.13ECh. 8.4 - Prob. 8.14ECh. 8.4 - Prob. 8.15ECh. 8.4 - Prob. 8.16ECh. 8.4 - Prob. 8.18ECh. 8.4 - Prob. 8.19ECh. 8.4 - Hotel Costs Even within a particular chain of...Ch. 8.4 - Prob. 8.21ECh. 8.5 - Find and interpret a 95% confidence interval for a...Ch. 8.5 - Find a 90% confidence interval for a population...Ch. 8.5 - Prob. 8.26ECh. 8.5 - Prob. 8.27ECh. 8.5 - Prob. 8.28ECh. 8.5 - Prob. 8.29ECh. 8.5 - Compare the confidence intervals in Exercise 8.29....Ch. 8.5 - Prob. 8.31ECh. 8.5 - Prob. 8.32ECh. 8.5 - Prob. 8.33ECh. 8.5 - Prob. 8.34ECh. 8.5 - Prob. 8.35ECh. 8.5 - Prob. 8.36ECh. 8.5 - Prob. 8.38ECh. 8.5 - What’s Normal? What is normal, when it comes to...Ch. 8.5 - Prob. 8.40ECh. 8.6 - Independent random samples were selected from...Ch. 8.6 - Prob. 8.42ECh. 8.6 - Prob. 8.43ECh. 8.6 - Prob. 8.44ECh. 8.6 - Prob. 8.45ECh. 8.6 - Prob. 8.46ECh. 8.6 - Prob. 8.47ECh. 8.6 - Prob. 8.48ECh. 8.6 - Prob. 8.49ECh. 8.6 - Prob. 8.50ECh. 8.6 - Hotel Costs Refer to Exercise 8.20. The means and...Ch. 8.6 - Noise and Stress To compare the effect of stress...Ch. 8.6 - Prob. 8.53ECh. 8.7 - Prob. 8.54ECh. 8.7 - Prob. 8.55ECh. 8.7 - Prob. 8.56ECh. 8.7 - Prob. 8.58ECh. 8.7 - Prob. 8.61ECh. 8.7 - Prob. 8.64ECh. 8.7 - Prob. 8.65ECh. 8.7 - Prob. 8.66ECh. 8.9 - Prob. 8.67ECh. 8.9 - Prob. 8.68ECh. 8.9 - Prob. 8.69ECh. 8.9 - Prob. 8.70ECh. 8.9 - Prob. 8.71ECh. 8.9 - Prob. 8.72ECh. 8.9 - Prob. 8.73ECh. 8.9 - Prob. 8.75ECh. 8.9 - Prob. 8.77ECh. 8.9 - Prob. 8.78ECh. 8.9 - Prob. 8.80ECh. 8.9 - Prob. 8.81ECh. 8.9 - Prob. 8.83ECh. 8 - Prob. 8.86SECh. 8 - Prob. 8.87SECh. 8 - Prob. 8.88SECh. 8 - Prob. 8.89SECh. 8 - Prob. 8.90SECh. 8 - Prob. 8.91SECh. 8 - Prob. 8.92SECh. 8 - Prob. 8.93SECh. 8 - Prob. 8.94SECh. 8 - Prob. 8.95SECh. 8 - Prob. 8.96SECh. 8 - Prob. 8.98SECh. 8 - Prob. 8.99SECh. 8 - Prob. 8.100SECh. 8 - Prob. 8.101SECh. 8 - Prob. 8.103SECh. 8 - Prob. 8.107SECh. 8 - Prob. 8.108SECh. 8 - Prob. 8.109SECh. 8 - Prob. 8.110SECh. 8 - Prob. 8.111SECh. 8 - Prob. 8.112SECh. 8 - Prob. 8.113SECh. 8 - Prob. 8.114SECh. 8 - Prob. 8.115SECh. 8 - Prob. 8.116SECh. 8 - Prob. 8.117SE
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