Introduction to Probability and Statistics
14th Edition
ISBN: 9781133103752
Author: Mendenhall, William
Publisher: Cengage Learning
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Chapter 2.3, Problem 2.15E
a.
To determine
To find: The
b.
To determine
To find:The value of
c.
To determine
To find: The variance and standard deviation.
d.
To determine
To find:Compare the variance and standard deviation by computing from part b and c.
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Example 4 (Part 2) We can use Statkey to take 50 different random samples of size 20 each, find the mean of
each sample, and compute a confidence interval for each one. The graph of the sampling distribution of the means
is on the left below, and that of the 50 confidence intervals is on the right.
1. What does each dot on the left hand dotplot represent?
StatKey Sampling Distribution for a Mean
Percent with Internet Access (Countries) ▾
Show Data Table Edit Data
Choose samples of size n =
20
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Change Column(s)
Generate 1 Sample
Generate 10 Samples
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Sampling Dotplot of Mean
Left Tail Two-Tail Right Tail
60
50
40
40
30
20
20
10
samples = 50
mean = 41.626
std. error = 5.089
:
.:
:
::
0
25
30
35
40
45
50
55
60
41.626
Data Plots
Confidence Intervals
95%->
Confidence Intervals
Coverage
48/50 = 96%
20
40
60
80
2. Circle the confidence intervals that failed to capture the true mean.
3. Circle the sample means that produced those…
Example 4 (Part 1) One of the datasets in the Lock book
contains information about 215 countries of the world. One
of the variables is the percentage of people in the country
who have access to the internet. We have data for 203 of
those countries. The plot on the right shows a dotplot of
the data.
1. What are the cases?
Population
n = 203, mean = 43.024
median = 43.5, stdev = 29.259
20
2. What does each dot on the dotplot represent?
15
10
5
20
40
43.024
60
80
3. What type of data is do we collect from the cases, quantitative or categorical?
Let x be a random variable that represents the percentage of successful free throws a professional basketball player makes in a season. Let y be a random variable that represents the percentage of successful field goals a professional basketball player makes in a season. A random sample of n =6 professional basketball players gave the following information.
x
63
79
70
80
84
87
y
46
49
45
55
57
58
Find Se. Round your answer to three decimal places.
Chapter 2 Solutions
Introduction to Probability and Statistics
Ch. 2.2 - You are given n=5 measurements: 0, 5, 1, 1,3. Draw...Ch. 2.2 - Prob. 2.2ECh. 2.2 - Prob. 2.3ECh. 2.2 - Auto Insurance The cost of automobile insurance...Ch. 2.2 - Prob. 2.5ECh. 2.2 - Prob. 2.6ECh. 2.2 - Prob. 2.7ECh. 2.2 - Prob. 2.8ECh. 2.2 - Prob. 2.9ECh. 2.2 - Prob. 2.10E
Ch. 2.2 - Prob. 2.11ECh. 2.2 - Prob. 2.12ECh. 2.3 - You are given n=5 measurements: 2, 1, 1,3,5. a....Ch. 2.3 - Prob. 2.14ECh. 2.3 - Prob. 2.15ECh. 2.3 - Prob. 2.16ECh. 2.3 - Prob. 2.17ECh. 2.3 - Utility Bills in Southern CaliforniaThe monthly...Ch. 2.5 - Prob. 2.19ECh. 2.5 - Prob. 2.20ECh. 2.5 - A distribution of measurements is relatively...Ch. 2.5 - Prob. 2.22ECh. 2.5 - Prob. 2.23ECh. 2.5 - Packaging Hamburger Meat The data listed here are...Ch. 2.5 - Breathing Rates Is your breathing rate normal?...Ch. 2.5 - Prob. 2.26ECh. 2.5 - Social Security Numbers A group of70 students were...Ch. 2.5 - Prob. 2.28ECh. 2.5 - Prob. 2.29ECh. 2.5 - Prob. 2.30ECh. 2.5 - Timber Tracts To estimate the amount of lumber in...Ch. 2.5 - Prob. 2.32ECh. 2.5 - Prob. 2.33ECh. 2.5 - Prob. 2.34ECh. 2.5 - Prob. 2.35ECh. 2.5 - Prob. 2.36ECh. 2.5 - Prob. 2.37ECh. 2.5 - Prob. 2.38ECh. 2.5 - Prob. 2.39ECh. 2.7 - Prob. 2.40ECh. 2.7 - Find the five-number summary and the IQR forthese...Ch. 2.7 - Given the following data set: 2.3, 1.0, 2.1, 6.5,...Ch. 2.7 - Given the following data set: .23, .30, .35, .41,...Ch. 2.7 - Construct a box plot for these data and...Ch. 2.7 - Construct a box plot for these data and...Ch. 2.7 - If you scored at the 69th percentile on a...Ch. 2.7 - Mercury Concentration in DolphinsEnvironmental...Ch. 2.7 - Hamburger Meat The weights (in pounds) of the 27...Ch. 2.7 - Comparing NFL Quarterbacks How does Aaron Rodgers,...Ch. 2.7 - Presidential Vetoes The set of presidential vetoes...Ch. 2.7 - Survival Times Altman and Bland report the...Ch. 2.7 - Utility Bills in Southern California, again The...Ch. 2.7 - What’s Normal? again Refer to Exercise1.67 and...Ch. 2 - Raisins The number of raisins in each of...Ch. 2 - Prob. 2.55SECh. 2 - Prob. 2.56SECh. 2 - A Recurring IIIness Refer to Exercise 1.26 and...Ch. 2 - Prob. 2.58SECh. 2 - Prob. 2.59SECh. 2 - Tuna Fish, again Refer to Exercise 2.8. Theprices...Ch. 2 - Prob. 2.61SECh. 2 - Chloroform According to the EPA, Chloroform, which...Ch. 2 - Prob. 2.63SECh. 2 - Sleep and the College Student How muchsleep do you...Ch. 2 - Prob. 2.65SECh. 2 - Prob. 2.66SECh. 2 - Polluted Seawater Petroleum pollution in seasand...Ch. 2 - Prob. 2.68SECh. 2 - Prob. 2.69SECh. 2 - Prob. 2.70SECh. 2 - Prob. 2.71SECh. 2 - Prob. 2.72SECh. 2 - Prob. 2.73SECh. 2 - Prob. 2.74SECh. 2 - TV Commercials The mean duration oftelevision...Ch. 2 - Prob. 2.76SECh. 2 - Prob. 2.77SECh. 2 - Prob. 2.78SECh. 2 - Prob. 2.79SECh. 2 - Prob. 2.80SECh. 2 - Prob. 2.81SECh. 2 - Prob. 2.82SECh. 2 - Prob. 2.83SECh. 2 - Prob. 2.84SECh. 2 - Prob. 2.85SE
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