Question 1

Let z be a normal random variable with mean 0 and standard deviation 1.What is P(1.3 < z < 2.3)?

Accepted Answer

A) 0.4032 
B) 0.9032 
C) 0.4893 
D) 0.0861 
E) 0.0086 
A) 0.4032 
B) 0.9032 
C) 0.4893 
D) 0.0861 
E) 0.0086

Question 2

Sure Stone Tire Company has established that the useful life of a particular brand of its automobile tires is normally distributed with a mean of 40,000 miles and a standard deviation of 5000 miles.What is the probability that a randomly selected tire of this brand has a life between 30,000 and 50,000 miles?

Accepted Answer

A) 0.5000 
B) 0.4772 
C) 0.9544 
D) 0.9772 
E) 1.0000 
A) 0.5000 
B) 0.4772 
C) 0.9544 
D) 0.9772 
E) 1.0000

Question 3

Inquiries arrive at a record message device according to a Poisson process of rate 15 inquiries per minute.The probability that it takes more than 12 seconds for the first inquiry to arrive is approximately _________

Accepted Answer

A) 0.05 
B) 0.75 
C) 0.25 
D) 0.27 
E) 0.73 
A) 0.05 
B) 0.75 
C) 0.25 
D) 0.27 
E) 0.73

Question 4

A uniform continuous distribution is also referred to as a rectangular distribution.

Accepted Answer

A) True 
 B)False

Question 5

The height of the rectangle depicting a uniform distribution is the probability of each outcome and it same for all of the possible outcomes

Accepted Answer

A) True 
 B)False

Question 6

A standard normal distribution has a mean of one and a standard deviation of three.

Accepted Answer

A) True 
 B)False

Question 7

Completion time (from start to finish)of a building remodeling project is normally distributed with a mean of 200 work-days and a standard deviation of 10 work-days.To be 99% sure that we will not be late in completing the project,we should request a completion time of _______ work-days.

Accepted Answer

A) 211 
B) 207 
C) 223 
D) 200 
E) 250 
A) 211 
B) 207 
C) 223 
D) 200 
E) 250

Question 8

The area to the left of the mean in any normal distribution is equal to _______.

Accepted Answer

A) the mean 
B) 1 
C) the variance 
D) 0.5 
E) -0.5 
A) the mean 
B) 1 
C) the variance 
D) 0.5 
E) -0.5

Question 9

Sure Stone Tire Company has established that the useful life of a particular brand of its automobile tires is normally distributed with a mean of 40,000 miles and a standard deviation of 5000 miles.What is the probability that a randomly selected tire of this brand has a life of at most 30,000 miles?

Accepted Answer

A) 0.5000 
B) 0.4772 
C) 0.0228 
D) 0.9772 
E) 1.0000 
A) 0.5000 
B) 0.4772 
C) 0.0228 
D) 0.9772 
E) 1.0000

Question 10

In a standard normal distribution,if the area under curve to the right of a z-value is 0.10,then the area to the left of the same z-value is -0.10.

Accepted Answer

A) True 
 B)False

Question 11

The expected (mean)life of a particular type of light bulb is 1,000 hours with a standard deviation of 50 hours.The life of this bulb is normally distributed.What is the probability that a randomly selected bulb would last longer than 1150 hours?

Accepted Answer

A) 0.4987 
B) 0.9987 
C) 0.0013 
D) 0.5013 
E) 0.5513 
A) 0.4987 
B) 0.9987 
C) 0.0013 
D) 0.5013 
E) 0.5513

Question 12

The probability that a call to an emergency help line is answered in less than 10 seconds is 0.8.Assume that the calls are independent of each other.Using the normal approximation for binomial with a correction for continuity,the probability that at least 75 of 100 calls are answered within 10 seconds is approximately _______

Accepted Answer

A) 0.8 
B) 0.1313 
C) 0.5235 
D) 0.9154 
E) 0.8687 
A) 0.8 
B) 0.1313 
C) 0.5235 
D) 0.9154 
E) 0.8687

Question 13

If x is uniformly distributed over the interval 8 to 12,inclusively (8 $\le$ x $\le$ 12),then P(x $\le$ 10)is __________________.

Accepted Answer

A) 0.750 
B) 0.000 
C) 0.333 
D) 0.500 
E) 0.900 
A) 0.750 
B) 0.000 
C) 0.333 
D) 0.500 
E) 0.900

Question 14

Within a range of z scores from -2 to +2,you can expect to find _______ per cent of the values in a normal distribution.

Accepted Answer

A) 95 
B) 99 
C) 68 
D) 34 
E) 100 
A) 95 
B) 99 
C) 68 
D) 34 
E) 100

Question 15

The average time between phone calls arriving at a call center is 30 seconds.Assuming that the time between calls is exponentially distributed,find the probability that less than two minutes elapse between calls.

Accepted Answer

A) 0.018 
B) 0.064 
C) 0.936 
D) 0.982 
E) 1.000 
A) 0.018 
B) 0.064 
C) 0.936 
D) 0.982 
E) 1.000

Question 16

Suppose the total time to fill a routine prescription at a local pharmacy is 35 minutes based on the time the physician places the order to the time it is dispensed.Assume the standard deviation is 11 minutes and the z score is 0.What is x?

Accepted Answer

A) -35.0 
B) 0.0 
C) 70.0 
D) 35.0 
E) -1.0 
A) -35.0 
B) 0.0 
C) 70.0 
D) 35.0 
E) -1.0

Question 17

Sure Stone Tire Company has established that the useful life of a particular brand of its automobile tires is normally distributed with a mean of 40,000 miles and a standard deviation of 5000 miles.What is the probability that a randomly selected tire of this brand has a life of at least 50,000 miles?

Accepted Answer

A) 0.0228 
B) 0.9772 
C) 0.5000 
D) 0.4772 
E) 1.0000 
A) 0.0228 
B) 0.9772 
C) 0.5000 
D) 0.4772 
E) 1.0000

Question 18

If x,the time (in minutes)to complete an change job at certain auto service station,is uniformly distributed over the interval 20 to 30,inclusively (20 $\le$ x $\le$ 30),then the probability that an oil change job is completed in less than or equal to 22 minutes,i.e.,P(x $\le$ 22)is __________________.

Accepted Answer

A) 0.200 
B) 0.300 
C) 0.000 
D) 0.250 
E) 1.000 
A) 0.200 
B) 0.300 
C) 0.000 
D) 0.250 
E) 1.000

Question 19

If x is uniformly distributed over the interval 8 to 12,inclusively (8 $\le$ x $\le$ 12),then the probability,P(10.0 $\le$ x $\le$ 11.5),is __________________.

Accepted Answer

A) 0.250 
B) 0.333 
C) 0.375 
D) 0.500 
E) 0.750 
A) 0.250 
B) 0.333 
C) 0.375 
D) 0.500 
E) 0.750

Question 20

If the number of parking spots at urban grocery stores is uniformly distributed over the interval 90 to 140,inclusively (90 $\le$ x $\le$ 140),then the standard deviation of this distribution is __________________.

Accepted Answer

A) 4.16 
B) 50 
C) 14.4 
D) 7.07 
E) 28.2 
A) 4.16 
B) 50 
C) 14.4 
D) 7.07 
E) 28.2

Let z be a normal random variable with mean 0 and standard deviation 1.What is P(1.3 < z < 2.3)?

Inquiries arrive at a record message device according to a Poisson process of rate 15 inquiries per minute.The probability that it takes more than 12 seconds for the first inquiry to arrive is approximately _________

A uniform continuous distribution is also referred to as a rectangular distribution.

The height of the rectangle depicting a uniform distribution is the probability of each outcome and it same for all of the possible outcomes

A standard normal distribution has a mean of one and a standard deviation of three.

Completion time (from start to finish)of a building remodeling project is normally distributed with a mean of 200 work-days and a standard deviation of 10 work-days.To be 99% sure that we will not be late in completing the project,we should request a completion time of _______ work-days.

The area to the left of the mean in any normal distribution is equal to _______.

In a standard normal distribution,if the area under curve to the right of a z-value is 0.10,then the area to the left of the same z-value is -0.10.

The expected (mean)life of a particular type of light bulb is 1,000 hours with a standard deviation of 50 hours.The life of this bulb is normally distributed.What is the probability that a randomly selected bulb would last longer than 1150 hours?

If x is uniformly distributed over the interval 8 to 12,inclusively (8 $\le$ x $\le$ 12),then P(x $\le$ 10)is __________________.

Within a range of z scores from -2 to +2,you can expect to find _______ per cent of the values in a normal distribution.

The average time between phone calls arriving at a call center is 30 seconds.Assuming that the time between calls is exponentially distributed,find the probability that less than two minutes elapse between calls.

Suppose the total time to fill a routine prescription at a local pharmacy is 35 minutes based on the time the physician places the order to the time it is dispensed.Assume the standard deviation is 11 minutes and the z score is 0.What is x?

If x is uniformly distributed over the interval 8 to 12,inclusively (8 $\le$ x $\le$ 12),then the probability,P(10.0 $\le$ x $\le$ 11.5),is __________________.

If the number of parking spots at urban grocery stores is uniformly distributed over the interval 90 to 140,inclusively (90 $\le$ x $\le$ 140),then the standard deviation of this distribution is __________________.

Introduction to Statistics

Charts and Graphs

Descriptive Statistics

Probability

Discrete Distributions

Sampling and Sampling Distributions

Statistical Inference: Estimation for Single Populations

Statistical Inference: Hypothesis Testing for Single Populations

Statistical Inferences About Two Populations

Analysis of Variance and Design of Experiments

Simple Regression Analysis and Correlation

Multiple Regression Analysis

Building Multiple Regression Models

Time-Series Forecasting and Index Numbers

Analysis of Categorical Data

Nonparametric Statistics

Statistical Quality Control

Decision Analysis

Filters

Exam 6: Continuous Distributions

Let z be a normal random variable with mean 0 and standard deviation 1.What is P(1.3 < z < 2.3)?

Inquiries arrive at a record message device according to a Poisson process of rate 15 inquiries per minute.The probability that it takes more than 12 seconds for the first inquiry to arrive is approximately _________

A uniform continuous distribution is also referred to as a rectangular distribution.

The height of the rectangle depicting a uniform distribution is the probability of each outcome and it same for all of the possible outcomes

A standard normal distribution has a mean of one and a standard deviation of three.

Completion time (from start to finish)of a building remodeling project is normally distributed with a mean of 200 work-days and a standard deviation of 10 work-days.To be 99% sure that we will not be late in completing the project,we should request a completion time of _______ work-days.

The area to the left of the mean in any normal distribution is equal to _______.

In a standard normal distribution,if the area under curve to the right of a z-value is 0.10,then the area to the left of the same z-value is -0.10.

The expected (mean)life of a particular type of light bulb is 1,000 hours with a standard deviation of 50 hours.The life of this bulb is normally distributed.What is the probability that a randomly selected bulb would last longer than 1150 hours?

If x is uniformly distributed over the interval 8 to 12,inclusively (8 ≤\le≤ x ≤\le≤ 12),then P(x ≤\le≤ 10)is __________________.

Within a range of z scores from -2 to +2,you can expect to find _______ per cent of the values in a normal distribution.

The average time between phone calls arriving at a call center is 30 seconds.Assuming that the time between calls is exponentially distributed,find the probability that less than two minutes elapse between calls.

Suppose the total time to fill a routine prescription at a local pharmacy is 35 minutes based on the time the physician places the order to the time it is dispensed.Assume the standard deviation is 11 minutes and the z score is 0.What is x?

If x is uniformly distributed over the interval 8 to 12,inclusively (8 ≤\le≤ x ≤\le≤ 12),then the probability,P(10.0 ≤\le≤ x ≤\le≤ 11.5),is __________________.

If the number of parking spots at urban grocery stores is uniformly distributed over the interval 90 to 140,inclusively (90 ≤\le≤ x ≤\le≤ 140),then the standard deviation of this distribution is __________________.

Introduction to Statistics

Charts and Graphs

Descriptive Statistics

Probability

Discrete Distributions

Sampling and Sampling Distributions

Statistical Inference: Estimation for Single Populations

Statistical Inference: Hypothesis Testing for Single Populations

Statistical Inferences About Two Populations

Analysis of Variance and Design of Experiments

Simple Regression Analysis and Correlation

Multiple Regression Analysis

Building Multiple Regression Models

Time-Series Forecasting and Index Numbers

Analysis of Categorical Data

Nonparametric Statistics

Statistical Quality Control

Decision Analysis

Filters

If x is uniformly distributed over the interval 8 to 12,inclusively (8 $\le$ x $\le$ 12),then P(x $\le$ 10)is __________________.

If x is uniformly distributed over the interval 8 to 12,inclusively (8 $\le$ x $\le$ 12),then the probability,P(10.0 $\le$ x $\le$ 11.5),is __________________.

If the number of parking spots at urban grocery stores is uniformly distributed over the interval 90 to 140,inclusively (90 $\le$ x $\le$ 140),then the standard deviation of this distribution is __________________.