Question 1

Let z be a normal random variable with mean 0 and standard deviation 1.What is P(-2.25 < z < -1.1)?

Accepted Answer

A) 0.3643 
B) 0.8643 
C) 0.1235 
D) 0.4878 
E) 0.5000 
A) 0.3643 
B) 0.8643 
C) 0.1235 
D) 0.4878 
E) 0.5000

Question 2

Normal distribution is a symmetrical distribution with its tails extending to infinity on either side of the mean.

Accepted Answer

A) True 
 B)False

Question 3

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

Accepted Answer

A) 0.4032 
B) 0.9032 
C) 0.0968 
D) 0.3485 
E) 0.5485 
A) 0.4032 
B) 0.9032 
C) 0.0968 
D) 0.3485 
E) 0.5485

Question 4

Let z be a normal random variable with mean 0 and standard deviation 1.What is P(z > 2.4)?

Accepted Answer

A) 0.4918 
B) 0.9918 
C) 0.0082 
D) 0.4793 
E) 0.0820 
A) 0.4918 
B) 0.9918 
C) 0.0082 
D) 0.4793 
E) 0.0820

Question 5

Since a normal distribution curve extends from minus infinity to plus infinity,the area under the curve is infinity.

Accepted Answer

A) True 
 B)False

Question 6

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 33 to 35 minutes,inclusively,i.e.,P(33 $\le$ x $\le$ 35)is __________________.

Accepted Answer

A) 0.5080 
B) 0.000 
C) 0.375 
D) 0.200 
E) 1.000 
A) 0.5080 
B) 0.000 
C) 0.375 
D) 0.200 
E) 1.000

Question 7

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..A z score was calculated for a number,and the z score is 3.4.What is x?

Accepted Answer

A) 37.4 
B) 72.4 
C) 0.00 
D) 68.0 
E) 2.0.8 
A) 37.4 
B) 72.4 
C) 0.00 
D) 68.0 
E) 2.0.8

Question 8

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 fewer than 1100 hours?

Accepted Answer

A) 0.4772 
B) 0.9772 
C) 0.0228 
D) 0.5228 
E) 0.5513 
A) 0.4772 
B) 0.9772 
C) 0.0228 
D) 0.5228 
E) 0.5513

Question 9

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.The probability that the project will be completed within 185 work-days is ______.

Accepted Answer

A) 0.0668 
B) 0.4332 
C) 0.5000 
D) 0.9332 
E) 0.9950 
A) 0.0668 
B) 0.4332 
C) 0.5000 
D) 0.9332 
E) 0.9950

Question 10

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 will be completed 24 minutes or more,i.e.,P(x $\le$ 24)is __________________.

Accepted Answer

A) 0.100 
B) 0.000 
C) 0.333 
D) 0.600 
E) 1.000 
A) 0.100 
B) 0.000 
C) 0.333 
D) 0.600 
E) 1.000

Question 11

Binomial distributions in which the sample sizes are large may be approximated by a Poisson distribution.

Accepted Answer

A) True 
 B)False

Question 12

Let z be a normal random variable with mean 0 and standard deviation 1.What is P(z < -2.1)?

Accepted Answer

A) 0.4821 
B) -0.4821 
C) 0.9821 
D) 0.0179 
E) -0.0179 
A) 0.4821 
B) -0.4821 
C) 0.9821 
D) 0.0179 
E) -0.0179

Question 13

The normal approximation for binomial distribution can be used when n=10 and p=1/5.

Accepted Answer

A) True 
 B)False

Question 14

If x,the time (in minutes)to complete an oil change job at certain auto service station,is uniformly distributed over the interval 20 to 30,inclusively (20 $\le$ x $\le$ 30),then the height of this distribution,f(x),is __________________.

Accepted Answer

A) 1/10 
B) 1/20 
C) 1/30 
D) 12/50 
E) 1/60 
A) 1/10 
B) 1/20 
C) 1/30 
D) 12/50 
E) 1/60

Question 15

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 -1.3.What is x?

Accepted Answer

A) 20.7 
B) 0.0 
C) -14.3 
D) 14.3 
E) -20.7 
A) 20.7 
B) 0.0 
C) -14.3 
D) 14.3 
E) -20.7

Question 16

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 25 to 28 minutes,inclusively,i.e.,P(25 $\le$ x $\le$ 28)is __________________.

Accepted Answer

A) 0.250 
B) 0.500 
C) 0.300 
D) 0.750 
E) 81.000 
A) 0.250 
B) 0.500 
C) 0.300 
D) 0.750 
E) 81.000

Question 17

The net profit from a certain investment is normally distributed with a mean of $2,500 and a standard deviation of $1,000.The probability that the investor will not have a net loss is _____________.

Accepted Answer

A) 0.4938 
B) 0.0062 
C) 0.9938 
D) 0.5062 
E) 0.0000 
A) 0.4938 
B) 0.0062 
C) 0.9938 
D) 0.5062 
E) 0.0000

Question 18

Let z be a normal random variable with mean 0 and standard deviation 1.The 75th percentile of z is ____________.

Accepted Answer

A) 0.6700 
B) -1.254 
C) 0.0000 
D) 1.2800 
E) 0.5000 
A) 0.6700 
B) -1.254 
C) 0.0000 
D) 1.2800 
E) 0.5000

Question 19

The exponential distribution is an example of _______.

Accepted Answer

A) a discrete distribution 
B) a continuous distribution 
C) a bimodal distribution 
D) a normal distribution 
E) a symmetrical distribution 
A) a discrete distribution 
B) a continuous distribution 
C) a bimodal distribution 
D) a normal distribution 
E) a symmetrical distribution

Question 20

A z score is the number of __________ that a value is from the mean.

Accepted Answer

A) variances 
B) standard deviations 
C) units 
D) miles 
E) minutes 
A) variances 
B) standard deviations 
C) units 
D) miles 
E) minutes

Let z be a normal random variable with mean 0 and standard deviation 1.What is P(-2.25 < z < -1.1)?

Normal distribution is a symmetrical distribution with its tails extending to infinity on either side of the mean.

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

Let z be a normal random variable with mean 0 and standard deviation 1.What is P(z > 2.4)?

Since a normal distribution curve extends from minus infinity to plus infinity,the area under the curve is infinity.

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..A z score was calculated for a number,and the z score is 3.4.What is x?

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 fewer than 1100 hours?

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.The probability that the project will be completed within 185 work-days is ______.

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 will be completed 24 minutes or more,i.e.,P(x $\le$ 24)is __________________.

Binomial distributions in which the sample sizes are large may be approximated by a Poisson distribution.

Let z be a normal random variable with mean 0 and standard deviation 1.What is P(z < -2.1)?

The normal approximation for binomial distribution can be used when n=10 and p=1/5.

If x,the time (in minutes)to complete an oil change job at certain auto service station,is uniformly distributed over the interval 20 to 30,inclusively (20 $\le$ x $\le$ 30),then the height of this distribution,f(x),is __________________.

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 -1.3.What is x?

The net profit from a certain investment is normally distributed with a mean of $2,500 and a standard deviation of $1,000.The probability that the investor will not have a net loss is _____________.

Let z be a normal random variable with mean 0 and standard deviation 1.The 75^th percentile of z is ____________.

The exponential distribution is an example of _______.

A z score is the number of __________ that a value is from the mean.

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(-2.25 < z < -1.1)?

Normal distribution is a symmetrical distribution with its tails extending to infinity on either side of the mean.

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

Let z be a normal random variable with mean 0 and standard deviation 1.What is P(z > 2.4)?

Since a normal distribution curve extends from minus infinity to plus infinity,the area under the curve is infinity.

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..A z score was calculated for a number,and the z score is 3.4.What is x?

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 fewer than 1100 hours?

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.The probability that the project will be completed within 185 work-days is ______.

Binomial distributions in which the sample sizes are large may be approximated by a Poisson distribution.

Let z be a normal random variable with mean 0 and standard deviation 1.What is P(z < -2.1)?

The normal approximation for binomial distribution can be used when n=10 and p=1/5.

If x,the time (in minutes)to complete an oil change job at certain auto service station,is uniformly distributed over the interval 20 to 30,inclusively (20 ≤\le≤ x ≤\le≤ 30),then the height of this distribution,f(x),is __________________.

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 -1.3.What is x?

The net profit from a certain investment is normally distributed with a mean of $2,500 and a standard deviation of $1,000.The probability that the investor will not have a net loss is _____________.

Let z be a normal random variable with mean 0 and standard deviation 1.The 75th percentile of z is ____________.

The exponential distribution is an example of _______.

A z score is the number of __________ that a value is from the mean.

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,the time (in minutes)to complete an oil change job at certain auto service station,is uniformly distributed over the interval 20 to 30,inclusively (20 $\le$ x $\le$ 30),then the height of this distribution,f(x),is __________________.

Let z be a normal random variable with mean 0 and standard deviation 1.The 75^th percentile of z is ____________.