Business Analytics chapter 4

 

The random variable X is known to be uniformly distributed between 2 and 12. Compute the standard deviation of X

• 2.887

• 3.464

• 8.333

• 12

 

The _____ probability distribution can be used to estimate the number of vehicles that go through an intersection during the lunch hour.

• binomial

• normal

• triangular

• Poisson

The center of a normal curve is _____.

• equal to the standard deviation

• the mean of the distribution

• always a positive number

• always equal to zero

Fast food restaurants pride themselves in being able to fill orders quickly. A study was done at a local fast food restaurant to determine how long it took customers to receive their order at the drive-thru. It was discovered that the time it takes for orders to be filled is exponentially distributed with a mean of 1.5 minutes. What is the probability that it takes less than one minute to fill an order?

• 0.7769

• 0.1813

• 0.6321

• 0.4866

 

The random variable X is known to be uniformly distributed between 2 and 12. Compute E(X), the expected value of the distribution.

• 4

• 7

• 6

• 5

An initial estimate of the probabilities of events is a _____ probability.

• conditional

• posterior

• prior

• empirical

 

In a normal distribution, which is greater, the mean or the median?

• Neither the mean nor the median (they are equal)

• Cannot be determined with the information provided

• Median

• Mean

A survey of 100 random high school students finds that 85 students watched the Super Bowl, 25 students watched the Stanley Cup Finals, and 20 students watched both games. How many students did not watch either game?

• 30

• 10

• 15

• 20

The event containing the outcomes belonging to A or B or both is the _____ of A and B.

• complement

• intersection

• Venn diagram

• union

 

The newest model of smart car is supposed to get excellent gas mileage. A thorough study showed that gas mileage (measured in miles per gallon) is normally distributed with a mean of 75 miles per gallon and a standard deviation of 10 miles per gallon. What is the probability that, if driven normally, the car will get 100 miles per gallon or better?

• 25%

• 0.6%

• 6%

• 2.5%