Question 1

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 2

For an exponential distribution,the mean and the median are equal.

Accepted Answer

A) True 
 B)False

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 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 4

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's net gain will be at least $2,000 is _____________.

Accepted Answer

A)  0.0000 
B)  0.3413 
C)  0.0005 
D)  0.0500 
E)  0.5000 
A)  0.0000 
B)  0.3413 
C)  0.0005 
D)  0.0500 
E)  0.5000

Question 5

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. the z-score for x = 46 is ________.

Accepted Answer

A)  1.0 
B)  -1.0 
C)  11 
D)  -11 
E)  .10 
A)  1.0 
B)  -1.0 
C)  11 
D)  -11 
E)  .10

Question 6

A normal distribution with a mean of zero and a standard deviation of 1 is called a null distribution.

Accepted Answer

A) True 
 B)False

Question 7

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 8

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 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

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

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,the mean and the median are equal.

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's net gain will be at least $2,000 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. the z-score for x = 46 is ________.

A normal distribution with a mean of zero and a standard deviation of 1 is called a null distribution.

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

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

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 P(x ≤\le≤ 11)is __________________.

For an exponential distribution,the mean and the median are equal.

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's net gain will be at least $2,000 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. the z-score for x = 46 is ________.

A normal distribution with a mean of zero and a standard deviation of 1 is called a null distribution.

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

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

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 P(x $\le$ 11)is __________________.

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