Question 1

Use the standard normal distribution to find $P ( - 2.50 < z < 1.50 )$

Accepted Answer

A)  .5496 
B)  .9270 
C)  .6167 
D)  .8822 
A)  .5496 
B)  .9270 
C)  .6167 
D)  .8822

Question 2

Explain why the following is or is not a valid probability distribution for the discrete random variable $x$

$$\begin{array} { | c | c | c | c | c | c | } 
\hline x & 1 & 3 & 5 & 7 & 9 \
\hline p ( x ) & .1 & .1 & .2 & .1 & .2 \
\hline
\end{array}$$

Accepted Answer

This is not a valid

Question 3

A local bakery has determined a probability distribution for the number of cheesecakes it sells in a given day. The distribution is as follows: $$\begin{array} { l | c c c c c } 
\text { Number sold in a day } & 0 & 5 & 10 & 15 & 20 \
\hline \text { Prob (Number sold) } & 0.06 & 0.2 & 0.13 & 0.08 & 0.53
\end{array}$$ Find the number of cheesecakes that this local bakery expects to sell in a day.

Accepted Answer

A)  20 
B)  14.16 
C)  14.1 
D)  10 
A)  20 
B)  14.16 
C)  14.1 
D)  10

Question 4

A recent study suggested that 70% of all eligible voters will vote in the next presidential election. Suppose 20 eligible voters were randomly selected from the population of all eligible voters. Use a binomial probability table to find the probability that more than 12 of the eligible voters sampled will vote in the next presidential election.

Accepted Answer

A)  0.772 
B)  0.228 
C)  0.392 
D)  0.887 
E)  0.608 
A)  0.772 
B)  0.228 
C)  0.392 
D)  0.887 
E)  0.608

Question 5

A machine is set to pump cleanser into a process at the rate of 6 gallons per minute. Upon inspection, it is learned that the machine actually pumps cleanser at a rate described by the uniform distribution over the interval 5.5 to 9.5 gallons per minute. Find the variance of the distribution.

Accepted Answer

A)  0.75 
B)  1.33 
C)  18.75 
D)  3.00 
A)  0.75 
B)  1.33 
C)  18.75 
D)  3.00

Question 6

$\text { Compute } \left( \begin{array} { l } 
9 \
4
\end{array} \right)$

Accepted Answer

A)  15,120 
B)  3024 
C)  84 
D)  126 
A)  15,120 
B)  3024 
C)  84 
D)  126

Question 7

A local newspaper claims that $70 \%$ of the items advertised in its classifieds section are sold within 1 week of the first appearance of the ad. To check the validity of the claim, the newspaper randomly selected $n = 25$ advertisements from last year's classifieds and contacted the people who placed the ads. They found that 16 of the 25 items sold within a week. Based on the newspaper's claim, is it likely to observe $x \leq 16$ who sold their item within a week? Use a binomial probability table.

Accepted Answer

Let @#LAT-DLM& the number of the 25 ads that resul

Question 8

Consider the given discrete probability distribution. Construct a graph for p $( x )$ $$\begin{array} { | c | c | c | c | c | c | c | } 
\hline x & 1 & 2 & 3 & 4 & 5 & 6 \
\hline p ( x ) & .30 & .25 & .20 & .15 & .05 & .05 \
\hline
\end{array}$$

Accepted Answer

The answer of Consider the given discrete probability distribution. Construct...

Question 9

Suppose $\mathrm { x }$ is a random variable best described by a uniform probability distribution with $\mathrm { c } = 30$ and $\mathrm { d } = 110$. Find $\mathrm { P } ( 70 \leq \mathrm { x } \leq 110 )$.

Accepted Answer

A)  0.4 
B)  0.5 
C)  0.6 
D)  0.05 
A)  0.4 
B)  0.5 
C)  0.6 
D)  0.05

Question 10

Which shape is used to represent areas for a normal distribution?

Accepted Answer

A)  Triangle 
B)  Circle 
C)  Rectangle 
D)  Bell curve 
A)  Triangle 
B)  Circle 
C)  Rectangle 
D)  Bell curve

Question 11

The university police department must write, on average, five tickets per day to keep department revenues at budgeted levels. Suppose the number of tickets written per day follows a Poisson distribution with a mean of 7.5. Find the probability that fewer than six tickets are written on a randomly selected day.

Accepted Answer

A)  0.621845 
B)  0.241436 
C)  0.378155 
D)  0.758564 
A)  0.621845 
B)  0.241436 
C)  0.378155 
D)  0.758564

Question 12

Assume that $x$ is a binomial random variable with $\mathrm { n } = 100$ and $\mathrm { p } = 0.60$. Use a normal approximation to find $P ( x \leq 55 )$.

Accepted Answer

A)  0.3212 
B)  0.1788 
C)  0.4247 
D)  0.1314 
A)  0.3212 
B)  0.1788 
C)  0.4247 
D)  0.1314

Question 13

You randomly select 7 students from a class with 15 male and 20 female students. What isthe probability that you will choose exactly 4 females?

Accepted Answer

The answer of You randomly select 7 students from a...

Use the standard normal distribution to find $P ( - 2.50 < z < 1.50 )$

Explain why the following is or is not a valid probability distribution for the discrete random variable $x$ x 1 3 5 7 9 p(x) .1 .1 .2 .1 .2

A local bakery has determined a probability distribution for the number of cheesecakes it sells in a given day. The distribution is as follows: Number sold in a day 0 5 10 15 20 Prob (Number sold) 0.06 0.2 0.13 0.08 0.53 Find the number of cheesecakes that this local bakery expects to sell in a day.

A machine is set to pump cleanser into a process at the rate of 6 gallons per minute. Upon inspection, it is learned that the machine actually pumps cleanser at a rate described by the uniform distribution over the interval 5.5 to 9.5 gallons per minute. Find the variance of the distribution.

$\text { Compute } \left( \begin{array} { l } 9 \\4\end{array} \right)$

Consider the given discrete probability distribution. Construct a graph for p $( x )$ x 1 2 3 4 5 6 p(x) .30 .25 .20 .15 .05 .05

Suppose $\mathrm { x }$ is a random variable best described by a uniform probability distribution with $\mathrm { c } = 30$ and $\mathrm { d } = 110$ . Find $\mathrm { P } ( 70 \leq \mathrm { x } \leq 110 )$ .

Which shape is used to represent areas for a normal distribution?

Assume that $x$ is a binomial random variable with $\mathrm { n } = 100$ and $\mathrm { p } = 0.60$ . Use a normal approximation to find $P ( x \leq 55 )$ .

You randomly select 7 students from a class with 15 male and 20 female students. What isthe probability that you will choose exactly 4 females?

Statistics, Data, and Statistical Thinking

Methods for Describing Sets of Data

Probability

Sampling Distributions

Inferences Based on a Single Sample: Estimation With Confidence Intervals

Inferences Based on a Single Sample: 355 Tests of Hypotheses

Inferences Based on Two Samples: Confidence Intervals and Tests of Hypotheses

Design of Experiments and Analysis of Variance

Categorical Data Analysis

Simple Linear Regression

Multiple Regression and Model Building

Methods for Quality Improvement: Statistical Process Control Available on CD

Time Series: Descriptive Analyses, Models, and Forecasting Available on CD

Nonparametric Statistics Available on CD

Filters

Exam 4: Random Variables and Probability Distributions

Use the standard normal distribution to find P(−2.50<z<1.50)P ( - 2.50 < z < 1.50 )P(−2.50<z<1.50)

Explain why the following is or is not a valid probability distribution for the discrete random variable xxx x 1 3 5 7 9 p(x) .1 .1 .2 .1 .2

A machine is set to pump cleanser into a process at the rate of 6 gallons per minute. Upon inspection, it is learned that the machine actually pumps cleanser at a rate described by the uniform distribution over the interval 5.5 to 9.5 gallons per minute. Find the variance of the distribution.

Compute (94)\text { Compute } \left( \begin{array} { l } 9 \\4\end{array} \right) Compute (94​)

Consider the given discrete probability distribution. Construct a graph for p (x)( x )(x) x 1 2 3 4 5 6 p(x) .30 .25 .20 .15 .05 .05

Suppose x\mathrm { x }x is a random variable best described by a uniform probability distribution with c=30\mathrm { c } = 30c=30 and d=110\mathrm { d } = 110d=110 . Find P(70≤x≤110)\mathrm { P } ( 70 \leq \mathrm { x } \leq 110 )P(70≤x≤110) .

Which shape is used to represent areas for a normal distribution?

Assume that xxx is a binomial random variable with n=100\mathrm { n } = 100n=100 and p=0.60\mathrm { p } = 0.60p=0.60 . Use a normal approximation to find P(x≤55)P ( x \leq 55 )P(x≤55) .

You randomly select 7 students from a class with 15 male and 20 female students. What isthe probability that you will choose exactly 4 females?

Statistics, Data, and Statistical Thinking

Methods for Describing Sets of Data

Probability

Sampling Distributions

Inferences Based on a Single Sample: Estimation With Confidence Intervals

Inferences Based on a Single Sample: 355 Tests of Hypotheses

Inferences Based on Two Samples: Confidence Intervals and Tests of Hypotheses

Design of Experiments and Analysis of Variance

Categorical Data Analysis

Simple Linear Regression

Multiple Regression and Model Building

Methods for Quality Improvement: Statistical Process Control Available on CD

Time Series: Descriptive Analyses, Models, and Forecasting Available on CD

Nonparametric Statistics Available on CD

Filters

Use the standard normal distribution to find $P ( - 2.50 < z < 1.50 )$

Explain why the following is or is not a valid probability distribution for the discrete random variable $x$ x 1 3 5 7 9 p(x) .1 .1 .2 .1 .2

$\text { Compute } \left( \begin{array} { l } 9 \\4\end{array} \right)$

Consider the given discrete probability distribution. Construct a graph for p $( x )$ x 1 2 3 4 5 6 p(x) .30 .25 .20 .15 .05 .05

Suppose $\mathrm { x }$ is a random variable best described by a uniform probability distribution with $\mathrm { c } = 30$ and $\mathrm { d } = 110$ . Find $\mathrm { P } ( 70 \leq \mathrm { x } \leq 110 )$ .

Assume that $x$ is a binomial random variable with $\mathrm { n } = 100$ and $\mathrm { p } = 0.60$ . Use a normal approximation to find $P ( x \leq 55 )$ .