100% satisfaction guarantee Immediately available after payment Both online and in PDF No strings attached
logo-home
Solutions for Statistical Reasoning for Everyday Life, 6th Edition by Bennett (All Chapters included) $29.49   Add to cart

Exam (elaborations)

Solutions for Statistical Reasoning for Everyday Life, 6th Edition by Bennett (All Chapters included)

1 review
 23 views  1 purchase
  • Course
  • Introduction to Statistics
  • Institution
  • Introduction To Statistics

Complete Solutions Manual for Statistical Reasoning for Everyday Life, 6th Edition by Jeff Bennett, William L. Briggs, Mario F. Triola ; ISBN13: 9780138032906.....(Full Chapters included and organized in reverse order from Chapter 10 to 1)...1. Speaking of Statistics 2. Measurement in Statistics ...

[Show more]

Preview 4 out of 136  pages

  • September 17, 2024
  • 136
  • 2024/2025
  • Exam (elaborations)
  • Questions & answers
  • Introduction to Statistics
  • Introduction to Statistics

1  review

review-writer-avatar

By: zautry • 3 weeks ago

Good answers and explanations. Has all of the answers as well.

reply-writer-avatar

By: mizhouubcca • 3 weeks ago

Thank you for your kind review! I’m glad you found the information useful. I look forward to your next visit!

avatar-seller
mizhouubcca
Statistical Reasoning for Everyday Life
6th Edition by Jeff Bennett



Complete Chapter Solutions Manual
are included (Ch 1 to 10)




** Immediate Download
** Swift Response
** All Chapters included

,Table of Contents are given below




1. Speaking of Statistics

2. Measurement in Statistics

3. Visual Displays of Data

4. Describing Data

5. A Normal World

6. Probability in Statistics

7. Correlation and Causality

8. Inferences from Samples to Populations

9. Hypothesis Testing

10. t Tests, Two-Way Tables, and ANOVA

,Solutions Manual organized in reverse order, with the last chapter
displayed first, to ensure that all chapters are included in this document.
(Complete Chapters included Ch10-1)
Section 10.1: The t Distribution for Inferences about a Mean 119

Chapter 10: Additional Topics in Inferential Statistics
Section 10.1: The t Distribution for Inferences about a Mean
1. The t distribution is a distribution that is quite similar to the normal distribution; its precise shape depends on
the sample size as well as on the sample mean and standard deviation. We can use the t distribution when the
population standard deviation is not known and the population is normally distributed, or when the population
standard deviation is not known and the sample size is greater than 30. The advantages of the t distribution are
that calculations can be done without knowing the population standard deviation and that the t distribution
accounts for the greater variability that arises with small sample sizes.
2. The number of degrees of freedom is n  1, which is the sample size minus 1. The number of degrees of
freedom is used to find the critical t values, which are used for constructing confidence intervals and testing
claims made about population means.

3. The margin of error is E  (t  s) n . The fundamental difference is that the formula for the margin of error
from Section 8.2 used 1.96 instead of t; the value 1.96 is from the normal distribution, whereas the value of t is
from the t distribution. The use of t yields better results because the t distribution is based on the sample size
instead of using the same constant of 1.96.
4. Use of the normal distribution requires that we know the value of the population standard deviation,  , but
that value is almost never known, so the t distribution is used much more often.
5. This statement does not make sense. This would be the case only if you also know (or can safely assume) that
the population is normally distributed and the population standard deviation is unknown.
6. This statement does not make sense. In reality, the population standard deviation is almost never known, so the
t distribution should be used.
7. This statement makes sense. Because the population is not normally distributed, the conditions for using the t
distribution require a sample size greater than 30.
8. This statement makes sense. The sample size is greater than 30, so use of the t distribution provides a
reasonable estimate of the population mean.
Concepts and applications
9. The number of degrees of freedom is n  1  16  1  15. From Table 10.1, the critical value is t  2.131.
t  s 2.131  10
The margin of error is E    5.3. The 95% confidence interval is x  E  130  5.3  124.7
n 16
to x  E  130  5.3  135.3, or 124.7    135.3.

10. The number of degrees of freedom is n  1  16  1  15. From Table 10.1, the critical value is t  2.131.
t  s 2.131  3.50
The margin of error is E    1.9 inches. The 95% confidence interval is
n 16
x  E  77.9  1.9  76.0 inches to x  E  77.9  1.9  79.8 inches, or 76.0 inches    79.8 inches.

11. The number of degrees of freedom is n  1  35  1  34. From Table 10.1, the critical value is t  2.032.
t  s 2.032  0.7
The margin of error is E    0.2 inch. The 95% confidence interval is
n 35
x  E  14.5  0.2  14.3 inches to x  E  14.5  0.2  14.7 inches, or 14.3 inches    14.7 inches.

12. The number of degrees of freedom is n  1  51  1  50. From Table 10.1, the critical value is t  2.009.
t  s 2.009  5.013
The margin of error is E    1.410 km. The 95% confidence interval is
n 51
x  E  9.808  1.410  8.398 km to x  E  9.808  1.410  11.218 km, or 8.398 km    11.218 km.

, 120 Chapter 10: Additional Topics in Inferential Statistics

13. a) The number of degrees of freedom is n  1  20  1  19. From Table 10.1, the critical value is t  2.093.
t  s 2.093  5629
The margin of error is E    $2634. The 95% confidence interval is
n 20
x  E  9004  2634  $6370 to x  E  9004  2634  $11, 638, or $6370    $11, 638.
b) Use the upper confidence limit of $11,638 as the worst possible hospital cost to the insurance company. One
could be even more conservative by using a 99% confidence interval (which would be wider). The upper
confidence limit would be higher yet.
14. a) The number of degrees of freedom is n  1  31  1  30. From Table 10.1, the critical value is t  2.042.
t  s 2.042  3.704
The margin of error is E    1.358F. The 95% confidence interval is
n 31
x  E  0.419  1.358  1.777F to x  E  0.419  1.358  0.939F, or 1.777F    0.939F.
b) Yes, the confidence interval includes zero. This means that zero degrees is a possible value of the mean of
the differences between the actual and forecast values. We cannot claim that the three-day forecast high
temperatures tend to be different from the actual high temperatures based simply on the sample mean.
15. a) The sample mean is x  0.121 gram/mile and the sample standard deviation is s  0.0389 gram/mile. The
number of degrees of freedom is n  1  7  1  6. From Table 10.1, the critical value is t  2.447.
t  s 2.447  0.0389
The margin of error is E    0.036 gram/mile. The 95% confidence interval is
n 7
x  E  0.121  0.036  0.085 gram/mile to x  E  0.121  0.036  0.157 gram/mile, or
0.085 gram/mile    0.157 gram/mile.
b) No, the claim does not appear to be valid. Because 0.165 gram/mile is not included in the confidence
interval, that value does not appear to be the mean.
16. a) The sample mean is x  121.75 minutes and the sample standard deviation is s  20.356 minutes. The
number of degrees of freedom is n  1  12  1  11. From Table 10.1, the critical value is t  2.201. The
t  s 2.201  20.356
margin of error is E    12.93 minutes. The 95% confidence interval is
n 12
x  E  121.75  12.93  108.8 minutes to x  E  121.75  12.93  134.7 minutes, or
108.8 minutes    134.7 minutes.
b) No, it is not reasonable. The data and the confidence interval suggest that some movies run longer than 130
minutes.
17. The sample mean is x  1130.2 cm3 and the sample standard deviation is s  117.4 cm3. The number of
degrees of freedom is n  1  10  1  9. From Table 10.1, the critical value is t  2.262. The margin of error is
t  s 2.262  117.4
E   84.0 cm3. The 95% confidence interval is x  E  1130.2  84.0  1046.2 cm3 to
n 10
x  E  1130.2  84.0  1214.2 cm3, or 1046.2 cm3    1214.2 cm3. Yes, the sample values appear to be
typical because they are all between 950 cm3 and 1800 cm3.
18. The sample mean is x  0.938 W/kg and the sample standard deviation is s  0.423 W/kg.
The number of degrees of freedom is n  1  11  1  10. From Table 10.1, the critical value is t  2.228.
t  s 2.228  0.423
The margin of error is E    0.284 W/kg.
n 11
The 95% confidence interval is x  E  0.938  0.284  0.654 W/kg to x  E  0.938  0.284  1.222 W/kg, or
0.654 W/kg    1.222 W/kg. Because the values in the confidence interval are all below 1.6 W/kg, it
appears that the mean amount of cell phone radiation is less than the FCC standard, but there could be
individual cell phones that exceed that standard.

The benefits of buying summaries with Stuvia:

Guaranteed quality through customer reviews

Guaranteed quality through customer reviews

Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.

Quick and easy check-out

Quick and easy check-out

You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.

Focus on what matters

Focus on what matters

Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!

Frequently asked questions

What do I get when I buy this document?

You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.

Satisfaction guarantee: how does it work?

Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.

Who am I buying these notes from?

Stuvia is a marketplace, so you are not buying this document from us, but from seller mizhouubcca. Stuvia facilitates payment to the seller.

Will I be stuck with a subscription?

No, you only buy these notes for $29.49. You're not tied to anything after your purchase.

Can Stuvia be trusted?

4.6 stars on Google & Trustpilot (+1000 reviews)

78998 documents were sold in the last 30 days

Founded in 2010, the go-to place to buy study notes for 14 years now

Start selling
$29.49  1x  sold
  • (1)
  Add to cart