Question 1

The standard error of the mean

Accepted Answer

A) is never larger than the standard deviation of the population. 
B) decreases as the sample size increases. 
C) measures the variability of the mean from sample to sample. 
D) All of the above. 
A) is never larger than the standard deviation of the population. 
B) decreases as the sample size increases. 
C) measures the variability of the mean from sample to sample. 
D) All of the above. D

Question 2

A manufacturer of power tools claims that the mean amount of time required to assemble their top-of-the-line table saw is 80 minutes with a standard deviation of 40 minutes.Suppose a random sample of 64 purchasers of this table saw is taken.So,the middle 95% of the sample means based on sample sizes of 64 will be between ________ and ________.

Accepted Answer

70.2 and 89.8 minutes

Question 3

True or False: The sample proportion is an unbiased estimate of the population proportion.

Accepted Answer

A) True 
 B)False  True

Question 4

To use the normal distribution to approximate the binomial distribution,we need ________ and ________ to be at least 5.

Accepted Answer

The answer of To use the normal distribution to approximate...

Question 5

The standard error of the population proportion will become larger

Accepted Answer

A) as population proportion approaches 0. 
B) as population proportion approaches 0.50. 
C) as population proportion approaches 1.00. 
D) as the sample size increases. 
A) as population proportion approaches 0. 
B) as population proportion approaches 0.50. 
C) as population proportion approaches 1.00. 
D) as the sample size increases.

Question 6

True or False: If the amount of gasoline purchased per car at a large service station has a population mean of 15 gallons and a population standard deviation of 4 gallons,and it is assumed that the amount of gasoline purchased per car is symmetric,there is approximately a 68.26% chance that a random sample of 16 cars will have a sample mean between 14 and 16 gallons.

Accepted Answer

A) True 
 B)False

Question 7

TABLE 7-4
According to a survey,only 15% of customers who visited the website of a major retail store made a purchase.Random sample sizes of 50 are selected.
-A study at a college in the west coast reveals that,historically,45% of the students are minority students.If random sample sizes of 75 are selected,the standard error of the proportion of students in the samples who are minority students is ________.

Accepted Answer

The answer of TABLE 7-4
According to a survey,only 15% of...

Question 8

True or False: The amount of bleach a machine pours into bottles has a mean of 36 oz.with a standard deviation of 0.15 oz.Suppose we take a random sample of 36 bottles filled by this machine.The sampling distribution of the sample mean will be approximately normal only if the population sampled is normal.

Accepted Answer

A) True 
 B)False

Question 9

True or False: A sampling distribution is a distribution for a statistic.

Accepted Answer

A) True 
 B)False

Question 10

Major league baseball salaries averaged $3.26 million with a standard deviation of $1.2 million in a recent year.Suppose a sample of 100 major league players was taken.Find the approximate probability that the mean salary of the 100 players exceeded $3.5 million.

Accepted Answer

A) approximately 0 
B) 0.0228 
C) 0.9772 
D) approximately 1 
A) approximately 0 
B) 0.0228 
C) 0.9772 
D) approximately 1

Question 11

True or False: The amount of time it takes to complete an examination has a left skewed distribution with a mean of 65 minutes and a standard deviation of 8 minutes.If 64 students were randomly sampled,the probability that the sample mean of the sampled students exceeds 71 minutes is approximately 0.

Accepted Answer

A) True 
 B)False

Question 12

A manufacturer of power tools claims that the mean amount of time required to assemble their top-of-the-line table saw is 80 minutes with a standard deviation of 40 minutes.Suppose a random sample of 64 purchasers of this table saw is taken.The mean of the sampling distribution of the sample mean is ________ minutes.

Accepted Answer

The answer of A manufacturer of power tools claims that...

Question 13

True or False: If the population distribution is skewed,in most cases the sampling distribution of the mean can be approximated by the normal distribution if the samples contain at least 30 observations.

Accepted Answer

A) True 
 B)False

Question 14

True or False: As the sample size increases,the standard error of the mean increases.

Accepted Answer

A) True 
 B)False

Question 15

True or False: The sample mean is an unbiased estimate of the population mean.

Accepted Answer

A) True 
 B)False

Question 16

Major league baseball salaries averaged $3.26 million with a standard deviation of $1.2 million in a recent year.Suppose a sample of 100 major league players was taken.Find the approximate probability that the mean salary of the 100 players was less than $2.5 million.

Accepted Answer

A) approximately 0 
B) 0.0151 
C) 0.9849 
D) approximately 1 
A) approximately 0 
B) 0.0151 
C) 0.9849 
D) approximately 1

Question 17

True or False: If the amount of gasoline purchased per car at a large service station has a population mean of 15 gallons and a population standard deviation of 4 gallons,and a random sample of 4 cars is selected,there is approximately a 68.26% chance that the sample mean will be between 13 and 17 gallons.

Accepted Answer

A) True 
 B)False

Question 18

True or False: The Central Limit Theorem is considered powerful in statistics because it works for any population distribution provided the sample size is sufficiently large and the population mean and standard deviation are known.

Accepted Answer

A) True 
 B)False

Question 19

TABLE 7-1
The time spent studying by students in the week before final exams follows a normal distribution with a standard deviation of 8 hours.A random sample of 4 students was taken in order to estimate the mean study time for the population of all students.
-Referring to Table 7-1,what is the probability that the sample mean is more than 3 hours below the population mean?

Accepted Answer

The answer of TABLE 7-1
The time spent studying by students...

Question 20

True or False: The standard error of the mean is also known as the standard deviation of the sampling distribution of the sample mean.

Accepted Answer

A) True 
 B)False

Exam 7: Sampling Distributions

The standard error of the mean

True or False: The sample proportion is an unbiased estimate of the population proportion.

To use the normal distribution to approximate the binomial distribution,we need ________ and ________ to be at least 5.

The standard error of the population proportion will become larger

True or False: A sampling distribution is a distribution for a statistic.

Major league baseball salaries averaged $3.26 million with a standard deviation of $1.2 million in a recent year.Suppose a sample of 100 major league players was taken.Find the approximate probability that the mean salary of the 100 players exceeded $3.5 million.

True or False: If the population distribution is skewed,in most cases the sampling distribution of the mean can be approximated by the normal distribution if the samples contain at least 30 observations.

True or False: As the sample size increases,the standard error of the mean increases.

True or False: The sample mean is an unbiased estimate of the population mean.

Major league baseball salaries averaged $3.26 million with a standard deviation of $1.2 million in a recent year.Suppose a sample of 100 major league players was taken.Find the approximate probability that the mean salary of the 100 players was less than $2.5 million.

True or False: The Central Limit Theorem is considered powerful in statistics because it works for any population distribution provided the sample size is sufficiently large and the population mean and standard deviation are known.

True or False: The standard error of the mean is also known as the standard deviation of the sampling distribution of the sample mean.

Defining and Collecting Data

Numerical Descriptive Measures

Basic Probability

Discrete Probability Distributions

The Normal Distribution and Other Continuous Distributions

Confidence Interval Estimation

Fundamentals of Hypothesis Testing: One-Sample Tests

Two-Sample Tests

Analysis of Variance

Chi-Square Tests and Nonparametric Tests

Simple Linear Regression

Introduction to Multiple Regression

Multiple Regression Model Building

Time-Series Forecasting

A Roadmap for Analyzing Data

Statistical Applications in Quality Management

Decision Making

Index Numbers

Chi-Square Tests for the Variance or Standard Deviation

Mcnemar Test for the Difference Between Two Proportions Related Samples

The Analysis of Means Anom

The Analysis of Proportions Anop

The Randomized Block Design

The Power of a Test

Estimation and Sample Size Determination for Finite Populations

Application of Confidence Interval Estimation in Auditing

Sampling From Finite Populations

The Normal Approximation to the Binomial Distribution

Counting Rules

Lets Get Started Big Things to Learn First

Filters

To use the normal distribution to approximate the binomial distribution,we need and to be at least 5.