Question 1

If x is uniformly distributed over the interval 8 to 12,inclusively (8 $\le$ x $\le$ 12),then the probability,P(13 $\le$ x $\le$ 15),is __________________.

Accepted Answer

A)  0.250 
B)  0.500 
C)  0.375 
D)  0.000 
E)  1.000 
A)  0.250 
B)  0.500 
C)  0.375 
D)  0.000 
E)  1.000 D

Question 2

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 $\ge$ 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 D

Question 3

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 B

Question 4

Let z be a normal random variable with mean 0 and standard deviation 1.The 90th percentile of z is ____________.

Accepted Answer

A)  1.645 
B)  -1.254 
C)  1.960 
D)  1.280 
E)  1.650 
A)  1.645 
B)  -1.254 
C)  1.960 
D)  1.280 
E)  1.650

Question 5

A z-score is the number of standard deviations that a value of a random variable is above or below the mean.

Accepted Answer

A) True 
 B)False

Question 6

Assuming an equal chance of a new baby being a boy or a girl (that is,p= 0.5),we would like to find the probability of 40 or more of the next 100 births at a local hospital will be boys.Using the normal approximation for binomial with a correction for continuity,we should use the z-score _______

Accepted Answer

A)  0.4 
B)  -2.1 
C)  0.6 
D)  2 
E)  -1.7 
A)  0.4 
B)  -2.1 
C)  0.6 
D)  2 
E)  -1.7

Question 7

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 8

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 9

Let x be a binomial random variable with n=50 and p=.3. The probability of less than or equal to13 successes,when using the normal approximation for binomial is ____ ____

Accepted Answer

A)  -.6172 
B) .3086 
C) 3.240 
D) .2676 
E) -.23224 
A)  -.6172 
B) .3086 
C) 3.240 
D) .2676 
E) -.23224

Question 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?

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 11

A correction for continuity must be made when approximating the binomial distribution problems using a normal distribution.

Accepted Answer

A) True 
 B)False

Question 12

If x is uniformly distributed over the interval 8 to 12,inclusively (8 $\le$ x $\le$ 12),then the probability,P(9 $\le$ x $\le$ 11)is __________________.

Accepted Answer

A)  0.250 
B)  0.500 
C)  0.333 
D)  0.750 
E)  1.000 
A)  0.250 
B)  0.500 
C)  0.333 
D)  0.750 
E)  1.000

Question 13

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 14

At a certain workstation in an assembly line,the time required to assemble a component is exponentially distributed with a mean time of 10 minutes.Find the probability that a component is assembled in 3 to 7 minutes?

Accepted Answer

A)  0.5034 
B)  0.2592 
C)  0.2442 
D)  0.2942 
E)  0.5084 
A)  0.5034 
B)  0.2592 
C)  0.2442 
D)  0.2942 
E)  0.5084

Question 15

Let x be a binomial random variable with n=35 and p=.20. If we use the normal distribution to approximate probabilities for this,we would use a mean of _______.

Accepted Answer

A)  35 
B)  20 
C)  70 
D)  7 
E)  3.5 
A)  35 
B)  20 
C)  70 
D)  7 
E)  3.5

Question 16

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 mean of this distribution is __________________.

Accepted Answer

A)  50 
B)  25 
C)  10 
D)  15 
E)  5 
A)  50 
B)  25 
C)  10 
D)  15 
E)  5

Question 17

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 18

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 19

If x is uniformly distributed over the interval 8 to 12,inclusively (8 $\le$ x $\le$ 12),then P(x < 7)is __________________.

Accepted Answer

A)  0.500 
B)  0.000 
C)  0.375 
D)  0.250 
E)  1.000 
A)  0.500 
B)  0.000 
C)  0.375 
D)  0.250 
E)  1.000

Question 20

Within a range of z scores from -1 to +1,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

If x is uniformly distributed over the interval 8 to 12,inclusively (8 $\le$ x $\le$ 12),then the probability,P(13 $\le$ x $\le$ 15),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 $\ge$ 24)is __________________.

Let z be a normal random variable with mean 0 and standard deviation 1.The 90^th percentile of z is ____________.

A z-score is the number of standard deviations that a value of a random variable is above or below the mean.

Assuming an equal chance of a new baby being a boy or a girl (that is,p= 0.5),we would like to find the probability of 40 or more of the next 100 births at a local hospital will be boys.Using the normal approximation for binomial with a correction for continuity,we should use the z-score _______

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

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.

Let x be a binomial random variable with n=50 and p=.3. The probability of less than or equal to13 successes,when using the normal approximation for binomial is

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?

A correction for continuity must be made when approximating the binomial distribution problems using a normal distribution.

If x is uniformly distributed over the interval 8 to 12,inclusively (8 $\le$ x $\le$ 12),then the probability,P(9 $\le$ x $\le$ 11)is __________________.

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.

At a certain workstation in an assembly line,the time required to assemble a component is exponentially distributed with a mean time of 10 minutes.Find the probability that a component is assembled in 3 to 7 minutes?

Let x be a binomial random variable with n=35 and p=.20. If we use the normal distribution to approximate probabilities for this,we would use a mean of _______.

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 mean of this distribution 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?

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

If x is uniformly distributed over the interval 8 to 12,inclusively (8 $\le$ x $\le$ 12),then P(x < 7)is __________________.

Within a range of z scores from -1 to +1,you can expect to find _______ per cent of the values in a normal distribution.

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

A Nalysis 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

If x is uniformly distributed over the interval 8 to 12,inclusively (8 ≤\le≤ x ≤\le≤ 12),then the probability,P(13 ≤\le≤ x ≤\le≤ 15),is __________________.

Let z be a normal random variable with mean 0 and standard deviation 1.The 90th percentile of z is ____________.

A z-score is the number of standard deviations that a value of a random variable is above or below the mean.

Assuming an equal chance of a new baby being a boy or a girl (that is,p= 0.5),we would like to find the probability of 40 or more of the next 100 births at a local hospital will be boys.Using the normal approximation for binomial with a correction for continuity,we should use the z-score _______

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

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.

Let x be a binomial random variable with n=50 and p=.3. The probability of less than or equal to13 successes,when using the normal approximation for binomial is ____ ____

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?

A correction for continuity must be made when approximating the binomial distribution problems using a normal distribution.

If x is uniformly distributed over the interval 8 to 12,inclusively (8 ≤\le≤ x ≤\le≤ 12),then the probability,P(9 ≤\le≤ x ≤\le≤ 11)is __________________.

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.

At a certain workstation in an assembly line,the time required to assemble a component is exponentially distributed with a mean time of 10 minutes.Find the probability that a component is assembled in 3 to 7 minutes?

Let x be a binomial random variable with n=35 and p=.20. If we use the normal distribution to approximate probabilities for this,we would use a mean of _______.

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 mean of this distribution 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?

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

If x is uniformly distributed over the interval 8 to 12,inclusively (8 ≤\le≤ x ≤\le≤ 12),then P(x < 7)is __________________.

Within a range of z scores from -1 to +1,you can expect to find _______ per cent of the values in a normal distribution.

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

A Nalysis 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 the probability,P(13 $\le$ x $\le$ 15),is __________________.

Let z be a normal random variable with mean 0 and standard deviation 1.The 90^th percentile of z is ____________.

Let x be a binomial random variable with n=50 and p=.3. The probability of less than or equal to13 successes,when using the normal approximation for binomial is

If x is uniformly distributed over the interval 8 to 12,inclusively (8 $\le$ x $\le$ 12),then the probability,P(9 $\le$ x $\le$ 11)is __________________.

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 mean of this distribution is __________________.

If x is uniformly distributed over the interval 8 to 12,inclusively (8 $\le$ x $\le$ 12),then P(x < 7)is __________________.