Question 1

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

Accepted Answer

A) True 
 B)False

Question 2

Suppose x is a normal random variable with mean 60 and standard deviation 2.A z score was calculated for a number,and the z score is 3.4.What is x?

Accepted Answer

A) 63.4 
B) 56.6 
C) 68.6 
D) 53.2 
E) 66.8 
A) 63.4 
B) 56.6 
C) 68.6 
D) 53.2 
E) 66.8

Question 3

If a continuous random variable x is uniformly distributed over the interval 8 to 12,inclusively,then P(x = exactly 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 4

The normal distribution is an example of ___.

Accepted Answer

A) a discrete distribution 
B) a continuous distribution 
C) a bimodal distribution 
D) an exponential distribution 
E) a binomial distribution 
A) a discrete distribution 
B) a continuous distribution 
C) a bimodal distribution 
D) an exponential distribution 
E) a binomial distribution

Question 5

The total area underneath any normal curve is equal to ___.

Accepted Answer

A) the mean 
B) one 
C) the variance 
D) the coefficient of variation 
E) the standard deviation 
A) the mean 
B) one 
C) the variance 
D) the coefficient of variation 
E) the standard deviation

Question 6

If x,the time (in minutes)to complete an change job at a 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 21.75 to 24.25 minutes,inclusively,i.e. ,P(21.75 $\le$ x $\le$ 24.25)is ___.

Accepted Answer

A) 0.250 
B) 0.333 
C) 0.375 
D) 0.000 
E) 1.000 
A) 0.250 
B) 0.333 
C) 0.375 
D) 0.000 
E) 1.000

Question 7

The net profit from a certain investment is normally distributed with a mean of $10,000 and a standard deviation of $5,000.The probability that the investor will not have a net loss is ___.

Accepted Answer

A) 0.4772 
B) 0.0228 
C) 0.9544 
D) 0.9772 
E) 1.0000 
A) 0.4772 
B) 0.0228 
C) 0.9544 
D) 0.9772 
E) 1.0000

Question 8

If x,the time (in minutes)to complete an oil change job at a 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 9

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

Let x be a binomial random variable with n=20 and p=.8.If we use the normal distribution to approximate probabilities for this,a correction for continuity should be made.To find the probability of more than 12 successes,we should find ___.

Accepted Answer

A) P(x>12.5) B) P(x>12) C) P(x>11.5) D) P(x<11.5) E) P(x < 12) A) P(x>12.5) B) P(x>12) C) P(x>11.5) D) P(x<11.5) E) P(x < 12)

Question 11

On Saturdays,cars arrive at Sam Schmitt's Scrub and Shine Car Wash at the rate of 6 cars per fifteen minute interval.The probability that at least 2 minutes will elapse between car arrivals is ___.

Accepted Answer

A) 0.0000 
B) 0.4493 
C) 0.1353 
D) 1.0000 
E) 1.0225 
A) 0.0000 
B) 0.4493 
C) 0.1353 
D) 1.0000 
E) 1.0225

Question 12

Suppose x is a normal random variable with mean 60 and standard deviation 2.A z score was calculated for a number,and the z score is -1.3.What is x?

Accepted Answer

A) 58.7 
B) 61.3 
C) 62.6 
D) 57.4 
E) 54.7 
A) 58.7 
B) 61.3 
C) 62.6 
D) 57.4 
E) 54.7

Question 13

On Saturdays,cars arrive at Sam Schmitt's Scrub and Shine Car Wash at the rate of 6 cars per fifteen minute interval.The probability that less than 10 minutes will elapse between car arrivals is ___.

Accepted Answer

A) 0.8465 
B) 0.9817 
C) 0.0183 
D) 0.1535 
E) 0.2125 
A) 0.8465 
B) 0.9817 
C) 0.0183 
D) 0.1535 
E) 0.2125

Question 14

If x,the time (in minutes)to complete an oil change job at a 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 15

If x is uniformly distributed over the interval 8 to 12,inclusively (8 $\le$ x $\le$ 12),then the mean of this distribution is ___.

Accepted Answer

A) 10 
B) 20 
C) 5 
D) 0 
E) unknown 
A) 10 
B) 20 
C) 5 
D) 0 
E) unknown

Question 16

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 17

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

Accepted Answer

A) True 
 B)False

Question 18

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

Accepted Answer

A) 0.750 
B) 0.000 
C) 0.333 
D) 0.500 
E) 1.000 
A) 0.750 
B) 0.000 
C) 0.333 
D) 0.500 
E) 1.000

Question 19

For an exponential distribution with a lambda (λ)equal to 4,the standard deviation is equal to ___.

Accepted Answer

A) 4 
B) 0.5 
C) 0.25 
D) 1 
E) 16 
A) 4 
B) 0.5 
C) 0.25 
D) 1 
E) 16

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

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

Suppose x is a normal random variable with mean 60 and standard deviation 2.A z score was calculated for a number,and the z score is 3.4.What is x?

If a continuous random variable x is uniformly distributed over the interval 8 to 12,inclusively,then P(x = exactly 10)is ___.

The normal distribution is an example of ___.

The total area underneath any normal curve is equal to ___.

The net profit from a certain investment is normally distributed with a mean of $10,000 and a standard deviation of $5,000.The probability that the investor will not have a net loss is ___.

If x,the time (in minutes)to complete an oil change job at a 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 $\ge$ 10)is ___.

Let x be a binomial random variable with n=20 and p=.8.If we use the normal distribution to approximate probabilities for this,a correction for continuity should be made.To find the probability of more than 12 successes,we should find ___.

On Saturdays,cars arrive at Sam Schmitt's Scrub and Shine Car Wash at the rate of 6 cars per fifteen minute interval.The probability that at least 2 minutes will elapse between car arrivals is ___.

Suppose x is a normal random variable with mean 60 and standard deviation 2.A z score was calculated for a number,and the z score is -1.3.What is x?

On Saturdays,cars arrive at Sam Schmitt's Scrub and Shine Car Wash at the rate of 6 cars per fifteen minute interval.The probability that less than 10 minutes will elapse between car arrivals is ___.

If x,the time (in minutes)to complete an oil change job at a 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 ___.

If x is uniformly distributed over the interval 8 to 12,inclusively (8 $\le$ x $\le$ 12),then the mean of this distribution is ___.

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

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

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

For an exponential distribution with a lambda (λ)equal to 4,the standard deviation is equal to ___.

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

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

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

Suppose x is a normal random variable with mean 60 and standard deviation 2.A z score was calculated for a number,and the z score is 3.4.What is x?

If a continuous random variable x is uniformly distributed over the interval 8 to 12,inclusively,then P(x = exactly 10)is ___.

The normal distribution is an example of ___.

The total area underneath any normal curve is equal to ___.

The net profit from a certain investment is normally distributed with a mean of $10,000 and a standard deviation of $5,000.The probability that the investor will not have a net loss is ___.

If x,the time (in minutes)to complete an oil change job at a 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 ≥\ge≥ 10)is ___.

Let x be a binomial random variable with n=20 and p=.8.If we use the normal distribution to approximate probabilities for this,a correction for continuity should be made.To find the probability of more than 12 successes,we should find ___.

On Saturdays,cars arrive at Sam Schmitt's Scrub and Shine Car Wash at the rate of 6 cars per fifteen minute interval.The probability that at least 2 minutes will elapse between car arrivals is ___.

Suppose x is a normal random variable with mean 60 and standard deviation 2.A z score was calculated for a number,and the z score is -1.3.What is x?

On Saturdays,cars arrive at Sam Schmitt's Scrub and Shine Car Wash at the rate of 6 cars per fifteen minute interval.The probability that less than 10 minutes will elapse between car arrivals is ___.

If x is uniformly distributed over the interval 8 to 12,inclusively (8 ≤\le≤ x ≤\le≤ 12),then the mean of this distribution is ___.

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

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

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

For an exponential distribution with a lambda (λ)equal to 4,the standard deviation is equal to ___.

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

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 a 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 $\ge$ 10)is ___.

If x is uniformly distributed over the interval 8 to 12,inclusively (8 $\le$ x $\le$ 12),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 $\le$ 11)is ___.