practice test

According to the Empirical Rule, approximately what is the probability that a number drawn at random from a standard normal distribution will be less than -2?

0.025

Numbers are drawn at random from a uniform distribution on 0 to 9. If 9 numbers are drawn, what is the probability at least one is less than 0.1? Round your answer to three decimal places.

0.096

What is the coefficient of variation for a Binomial distribution with 34 trials and probability 0.75 of success? Round your answer to two decimal places. Write your answer as a decimal, not as a percentage.

0.1

A person's credit score is an attempt to measure the risk that person poses as a borrower or renter. The higher the score, the less risky. Assume that the average credit scores is 702 with a standard deviation of 52 and the distribution of credit scores is normally distributed. What is the probability a random person will have a credit score between 734 and 757? Round your answer to two decimal places.

0.12

Dinners at four star restaurants in a certain city cost on average $45 with a standard deviation of $18 and are normally distributed. You go out to eat at random at these restaurants 14 times. What is the probability that the average you spend is greater than $50? Round your answer to two decimal places.

0.14

Suppose that weights in pounds of bags of flour follow a normal distribution with a standard deviation of 0.5 lbs. If 8% of bags are heavier than 122 lbs, what is the mean of this distribution? Round to two decimal places.

121.3

A pizza shop makes pizzas with 3 types of crust, 3 types of sauce, and 9 types of toppings. How many different pizzas can be made using one of the crust types, one of the sauce types, and two different topping types?

324

In how many ways can you select a committee of three people out of a club with 14 members?

364

Which of the following is not a continuous distribution? binomial exponential normal uniform

binomial

The probability of a set of values in a continuous distribution can be computed by ___________. A) calculating the area under the pdf curve B) using the =BINOM.DIST(X,MEAN,SD,TRUE) function in Excel. C) calculating counting the number of values in the set and dividing by the total number of values. D) using the =NORM.DIST(X,MEAN,SD,FALSE) function in Excel.

calculating the area under the pdf curve

When p is less than 0.5, the binomial distribution will be ____________. right-skewed symmetric uniform left-skewed

right-skewed

The difference between the sample mean and the population mean is called the ______________. The standard deviation of the sample mean is called the _______________.

sampling error, standard error of the mean

When p is equal to 0.5, the binomial distribution will be ____________. uniform right-skewed symmetric left-skewed

symmetric

Suppose you can pay $1 to participate in one of two gambling schemes: the state Pick-3 Lottery or betting on red in Roulette at the Casino. In Pick-3 you can win $500 if you pick all three numbers which has probability 0.001 of occurring; otherwise you get nothing. In Roulette, you can win $2 betting on red which has probability18/38 of occurring; otherwise you get nothing. Calculate the Expected Monetary Value for each game accounting for the money you spent to play the game. Enter the larger amount as your answer. Enter the amount as a number (two cents would be entered as 0.02, for example). Round to two decimal places.

-.05

Suppose Pr[A] = 0.4Pr[A]=0.4 and Pr[B|A] = 0.7Pr[B∣A]=0.7. What is Pr[A \cap B]Pr[A∩B]? Round your answer to two decimal places.

0.28

An exam has 28 questions. Assume that the student's ability to respond correctly to the questions is independent from question to question with probability 0.48 of being correct. What is the probability that the student gets fewer than 15 questions correct? Round your answer to two decimal places.

0.66

Assume that AA andBB are events with P\left(A\right)=0.53P(A)=0.53 and P\left(B\right)=0.43P(B)=0.43. What is P\left(A \cup B\right)P(A∪B) assuming that AA and BB are independent? Round your answer to three decimal places.

0.732

According to a recent survey, the average daily rate for a luxury hotel in a popular tourist destination is $246. Assume that daily rates follow a normal distribution with a standard deviation of 64. What is the probability that a randomly selected hotel's daily rate will be less than $350? Round your answer to two decimal places.

0.95

For a population with mean 341 and standard deviation 13, calculate the standard error of the mean for a sample size of 128. Round your answer to two decimal places.

1.149

What is the percentile rank of 22 among the data: 7, 23, 27, 41, 51, 56, 67, 76, 89? Use percentiles from 0-100% and round your answer to 1 decimal place.

19.3

Suppose the boarding process for a train is uniformly distributed with a minimum time of 11 and a maximum time of 45 minutes. What is the Pth percentile of this distribution if P is 54? Round your answer to one decimal place.

19.36

What is the standard deviation of the following discrete probability distribution? Round your answer to 2 decimal places. Practice copying and pasting from a table like the one below in Canvas to Excel. #28 on practice exam

20.48

Suppose that the average grade in this course is 79. A sample of five students give the following grades: 96, 78, 100, 99, 66. What is the sampling error? Round your answer to one decimal place.

8.8

In which of the following distribution is it always true that the 50th percentile is the same as the median? A left-skewed distribution. A right-skewed distribution A symmetrical distribution. Any distribution No distribution

Any distribution

Consider a binomial distribution where n is held constant and p=0.5, the standard deviation will decrease if _________. A) p increases B) p increases or decreases C) p decreases

B) p increases or decreases

Which of the following methods is most likely to have an issue with periodicity? Simple Random Sampling Stratified Sampling Cluster Sampling Systematic Sampling

Systematic Sampling

In the standard normal distribution, the mean is equal to 1 and the standard deviation is equal to 0. True or False?

True