Introduction to Statistics and Data Analysis
5th Edition
ISBN: 9781305445963
Author: PECK
Publisher: Cengage
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Chapter 9.2, Problem 19E
a.
To determine
Find and interpret the 90% confidence interval for the proportion of all people from Country A between the ages 8–18 who own a cell phone.
b.
To determine
Find and interpret the 90% confidence interval for the proportion of all people from Country A between the ages 8-18 who own a MP3 music player.
c.
To determine
Explain how the 90% confidence interval in Part (b) is narrower than a 90% confidence interval in Part (a).
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Exercise 6-6 (Algo) (LO6-3)
The director of admissions at Kinzua University in Nova Scotia estimated the distribution of student admissions for the fall semester on the basis of past experience.
Admissions
Probability
1,100
0.5
1,400
0.4
1,300
0.1
Click here for the Excel Data File
Required:
What is the expected number of admissions for the fall semester?
Compute the variance and the standard deviation of the number of admissions.
Note: Round your standard deviation to 2 decimal places.
1. Find the mean of the x-values (x-bar)
and the mean of the y-values (y-bar) and write/label each here:
2. Label the second row in the table using proper notation; then, complete the table. In the fifth and sixth
columns, show the 'products' of what you're multiplying, as well as the answers.
X
y
x minus x-bar y minus y-bar (x minus x-bar)(y minus y-bar)
(x minus x-bar)^2
xy
16
20
34
4-2
5 2
3. Write the sums that represents Sxx and Sxy in the table, at the bottom of their respective columns.
4. Find the slope of the Regression line: bi
=
(simplify your answer)
5. Find the y-intercept of the Regression line, and then write the equation of the Regression line.
Show your work. Then, BOX your final answer. Express your line as "y-hat equals...
Chapter 9 Solutions
Introduction to Statistics and Data Analysis
Ch. 9.1 - Three different statistics are being considered...Ch. 9.1 - a. Why is an unbiased statistic generally...Ch. 9.1 - Prob. 3ECh. 9.1 - Prob. 4ECh. 9.1 - Each person in a random sample of 20 students at a...Ch. 9.1 - Suppose that each of 935 smokers received a...Ch. 9.1 - Given below are the sodium contents (in mg) for...Ch. 9.1 - A random sample of n = 12 four-year-old red pine...Ch. 9.1 - A random sample of 10 houses heated with natural...Ch. 9.2 - Prob. 10E
Ch. 9.2 - The formula used to calculate a large-sample...Ch. 9.2 - Prob. 12ECh. 9.2 - Discuss how each of the following factors affects...Ch. 9.2 - Prob. 14ECh. 9.2 - Based on data from a survey of 1200 randomly...Ch. 9.2 - Prob. 16ECh. 9.2 - If a hurricane was headed your way, would you...Ch. 9.2 - Prob. 18ECh. 9.2 - Prob. 19ECh. 9.2 - Prob. 20ECh. 9.2 - Prob. 21ECh. 9.2 - Prob. 22ECh. 9.2 - Prob. 23ECh. 9.2 - Prob. 24ECh. 9.2 - Prob. 25ECh. 9.2 - Prob. 26ECh. 9.2 - Prob. 27ECh. 9.2 - The Gallup Organization conducts an annual survey...Ch. 9.2 - The article Hospitals Dispute Medtronic Data on...Ch. 9.2 - Prob. 30ECh. 9.2 - A discussion of digital ethics appears in the...Ch. 9.2 - In spite of the potential safety hazards, some...Ch. 9.2 - Prob. 33ECh. 9.3 - Given a variable that has at distribution with the...Ch. 9.3 - The formula used to calculate a confidence...Ch. 9.3 - USA TODAY reported that the average amount of...Ch. 9.3 - Samples of two different models of cars were...Ch. 9.3 - Prob. 38ECh. 9.3 - In a study of academic procrastination, the...Ch. 9.3 - Medical research has shown that repeated wrist...Ch. 9.3 - Prob. 41ECh. 9.3 - Prob. 42ECh. 9.3 - Suppose that a random sample of 50 bottles of a...Ch. 9.3 - Prob. 44ECh. 9.3 - The article The Association Between Television...Ch. 9.3 - Prob. 46ECh. 9.3 - Because of safety considerations, in May 2003 the...Ch. 9.3 - Example 9.3 gave the following airborne times (in...Ch. 9.3 - Prob. 49ECh. 9.3 - Five students visiting the student health center...Ch. 9.3 - The Bureau of Alcohol, Tobacco, and Firearms...Ch. 9.3 - The formula described in this section for...Ch. 9.4 - The following quote is from the article Credit...Ch. 9.4 - Authors of the news release titled Major Gaps...Ch. 9.4 - The paper The Curious Promiscuity of Queen Honey...Ch. 9 - Prob. 56CRCh. 9 - Prob. 57CRCh. 9 - Prob. 58CRCh. 9 - Prob. 59CRCh. 9 - Prob. 60CRCh. 9 - Prob. 61CRCh. 9 - A manufacturer of small appliances purchases...Ch. 9 - Prob. 63CRCh. 9 - A manufacturer of college textbooks is interested...Ch. 9 - Prob. 65CRCh. 9 - The confidence intervals presented in this chapter...Ch. 9 - Prob. 67CRCh. 9 - The interval from 2.33 to 1.75 captures an area of...Ch. 9 - Prob. 69CR
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