Introductory Statistics (2nd Edition)
2nd Edition
ISBN: 9780321978271
Author: Robert Gould, Colleen N. Ryan
Publisher: PEARSON
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Textbook Question
Chapter 3, Problem 19SE
Children’s Ages (Example 6) Mrs. Johnson’s children 2,2,3, and 5 years of age.
a. Calculate the standard deviation of their current ages.
b. Without doing any calculation, indicate whether the standard deviation of the ages in 20
years will be larger, smaller, or the same as the standard deviation of their current ages.
Check your answer by calculating the standard deviation of the ages in 20 years. Explain
how adding 20 to each number affects the standard deviation.
c. Find the
d. Without doing any calculation, indicate whether the mean age in 20 years will be larger, smaller, or about the same as the mean of the current ages. Confirm your answer, and describe how adding 20 to each number affects the mean.
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Students have asked these similar questions
Question 3
The following stem-and-leaf displays the weekly salary of employees at this firm.
Stem-and-Leaf Display
Leaf Unit = 10.0
N=x
5
3 00123
12 4 0125888
(y)
5 11234456777
z
6 13568
5
7 154
2
8 46
i.
Determine the value of x, y and z.
[3]
ii. What is the value of the median?
[2]
iii.
Find the mode of this data set.
iv.
Calculate the range
[1]
[2]
Let Y be a continuous RV with PDF
otherwise
Find the CDF, Fry), of Y .
Find an expression for pth, p € (0, 1), quantile of the distribution.
Find E(Y) and V(Y).
Find E(-2Y + 1) and V(-3Y - 2).
Find E(Y3).
Let X be a continuous RV with CDF
Find P(X < 0), P(-1 < X < 1) and P(0.5 < X).
Based on your answers to the above questions, what is the median of the distribu-tion? Why
Find the PDF, fx (x), of X.
Chapter 3 Solutions
Introductory Statistics (2nd Edition)
Ch. 3 - Earnings A sociologist says, “Typically, men in...Ch. 3 - Houses A real estate agent claims that all things...Ch. 3 - Age of CEOs (Example) the histogram shows the ages...Ch. 3 - Televisions The histogram shows the number of...Ch. 3 - Billionaires According to Forbes.com, the numbers...Ch. 3 - Billionaires According to Forbes.com, the numbers...Ch. 3 - Paid Vacation Days (Example 2) This list...Ch. 3 - Children of First Ladies This list represents the...Ch. 3 - Ages of Presidents at Inauguration At their...Ch. 3 - Ages of Chief Justices at Installation At their...
Ch. 3 - Weight Loss (Example 3) The table shows Minitab...Ch. 3 - Education of Father and Mother The table shows...Ch. 3 - Surfing College students and surfers Rex Robinson...Ch. 3 - Eating Out College student Jacqueline Loya asked a...Ch. 3 - Real state price (Example) look at the two...Ch. 3 - Dice The histogram contain data with a range of 1...Ch. 3 - Birth Weights (Example 5) The mean birth weigh for...Ch. 3 - Birth Length The mean birth length for U.S....Ch. 3 - Children’s Ages (Example 6) Mrs. Johnson’s...Ch. 3 - Pay Rate in Different Currencies The pay rates for...Ch. 3 - Olympics In the most recent summer Olympics, do...Ch. 3 - Weights Suppose you have a data set with the...Ch. 3 - Brain Size The brain size (in hundreds of...Ch. 3 - Happiness A survey on StatCrunch asked people to...Ch. 3 - Drinkers The number of alcoholic drinks per week...Ch. 3 - Prob. 26SECh. 3 - Violent Crime: West (Example 7) In 2011, the mean...Ch. 3 - Violent Crime: East In 2011, the mean rate of...Ch. 3 - Property Crime (Example 8) In 2011, the mean...Ch. 3 - Property Crime In 2011, the mean property crime...Ch. 3 - Heights and z-Scores The dotplot shows heights of...Ch. 3 - Heights Refer to the dotplot in the previous...Ch. 3 - Unusual IQs (Example 9) Wechsler IQ tests have a...Ch. 3 - Lengths of Pregnancy Distributions of gestation...Ch. 3 - Low-Birth-Weight Babies (Example 10) Babies born...Ch. 3 - Birth Lengths Babies born after 40 weeks gestation...Ch. 3 - Women's Heights Assume that women's heights have a...Ch. 3 - SATs The quantitative portion of the SAT exam has...Ch. 3 - Name two measures of the center of a distribution,...Ch. 3 - Name two measures of the variation of a...Ch. 3 - Pixar Animated Movies (Example 11) The ten...Ch. 3 - DreamWorks Animated Movies The ten top-grossing...Ch. 3 - Pixar Animated Movies Again (Example 12) Find the...Ch. 3 - Dreamworks Animated Movies Find the median and...Ch. 3 - Prob. 45SECh. 3 - Drinks The number of alcoholic drinks per week is...Ch. 3 - Outliers a. In your own words, describe to someone...Ch. 3 - Center and Variation When you are comparing two...Ch. 3 - An Error A dieter recorded the number of calories...Ch. 3 - Baseball Strike In 1994, Major League Baseball...Ch. 3 - Heads The graphs show the circumferences of heads...Ch. 3 - House Prices The graphs show the house prices (in...Ch. 3 - Shoes (Example 14) The histograms show the number...Ch. 3 - Tax Rate A StatCrunch survey asked people what...Ch. 3 - Regional Population Density The figure shows the...Ch. 3 - Property Crime Rates The boxplot shows the...Ch. 3 - City Temperatures The boxplot shows temperatures...Ch. 3 - Brain Size The boxplots show the brain size (in...Ch. 3 - Matching Boxplots and Histograms a. Report the...Ch. 3 - Matching Boxplots and Histograms Match each of the...Ch. 3 - Sleep Time of Animals Data at this text's website...Ch. 3 - BA Percentage The data show the percentage of...Ch. 3 - Tall Buildings The dotplot shows the distribution...Ch. 3 - Passing the Bar Exam The dotplot shows the...Ch. 3 - Exam Scores The five-number summary for a...Ch. 3 - Exam Scores The five-number summary for a...Ch. 3 - Death Row: South (Example 15) The table shows the...Ch. 3 - Death Row: West The table shows the numbers of...Ch. 3 - Head Circumference (Example 16) Following are head...Ch. 3 - Heights of Sons and Dads The data at this text’s...Ch. 3 - Final Exam Grades The data that follow are final...Ch. 3 - Speeding Tickets College students Diane Glover and...Ch. 3 - Heights The following graph shows the heights for...Ch. 3 - Marathon Times The following histogram of marathon...Ch. 3 - Soda Consumption A StatCrunch survey asked people...Ch. 3 - Holiday Spending A StatCrunch survey asked people...Ch. 3 - a. State an approximate value for the mean height...Ch. 3 - Ideal Family In 2012, the General Social Survey...Ch. 3 - For exercises 3.85 through 3.88, construct two...Ch. 3 - For exercises 3.85 through 3.88, construct two...Ch. 3 - For exercises 3.85 through 3.88, construct two...Ch. 3 - 3.79-3.82 construct two sets of numbers with at...Ch. 3 - Population Density Data were recorded for each of...Ch. 3 - Population Increase Data were recorded for each of...Ch. 3 - Prob. 85CRECh. 3 - Eating Out, Again College student Jacqueline Loya...Ch. 3 - Study Hours A group of 50 statistics students, 25...Ch. 3 - Driving Accidents College student Sandy Hudson...Ch. 3 - Exam Scores An exam has a mean of 70 and a...Ch. 3 - Boys’ Heights Three-year-old boys in the United...Ch. 3 - SAT and ACT Scores Quantitative SAT scores have a...Ch. 3 - Children’s Heights Mrs. Diaz has two children: a...Ch. 3 - Students’ Ages Here are the ages of some students...Ch. 3 - House Prices The figure, which is from data taken...
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