Statistics Chap 5 - Probability Distributions

What type of probability distribution will most likely be used to analyze warranty repair needs on new cars in the following problem? The service manager for a new automobile dealership reviewed dealership records of the past 20 sales of new cars to determine the number of warranty repairs he will be called on to perform in the next 30 days. Corporate reports indicate that the probability any one of their new cars needs a warranty repair in the first 30 days is 0.035. The manager assumes that calls for warranty repair are independent of one another and is interested in predicting the number of warranty repairs he will be called on to perform in the next 30 days for this batch of 20 new cars sold.

Binomial distribution.

The smallest number of possible successes in a Poisson distribution is:

0

The smallest number of possible successes in a binomial distribution is:

0

Given that X is a normally distributed random variable with a mean of 50 and a standard deviation of 2, the probability that X is between 47 and 54 is _________________

0.9104

The sum of the probabilities of all the events in a probability distribution is equal to:

1

What is one of the concepts that is true of normal distribution?

About two-thirds of the observations fall within one standard deviation of the mean.

Whenever p = 0.5, the binomial distribution will:

Always be symmetric.

If a particular set of data is approximately normally distributed, you would find that approximately:

Approximately 2 of every 3 observations would fall between 1 standard deviation around the mean.

A computer lab at a university has ten personal computers. Based on past experience, the probability that any one of them will require repair on a given day is 0.05. To find the probability that exactly two of the computers will require repair on a given day you can use what probability distribution?

Binomial distribution.

A multiple-choice test has 25 questions. There are four choices for each question. A student who has not studied for the test decides to answer all questions by randomly choosing one of the four choices. What probability distribution can be used be used to compute his chance of correctly answering at least 15 questions?

Binomial distribution.

What type of probability distribution will the consulting firm most likely employ to analyze the insurance claims in the following problem? An insurance company has called a consulting firm to determine whether the company has an unusually high number of false insurance claims. It is known that the industry proportion for false claims is 6%. The consulting firm has decided to randomly and independently sample 50 of the company's insurance claims. They believe that the number of claims from the sample, 50 of which are false, will yield the information the company desires.

Binomial distribution.

Based on past experience, the time you spend on emails per day has a mean of 30 minutes and a standard deviation of 10 minutes. To compose the probability of spending at least 12 minutes on emails, you can use what probability distribution?

Normal distribution.

The mean number of customers who arrive per minute at any one of the checkout counters of a grocery store is 1.8. What probability distribution can be used to find out the probability that there will be no customers arriving at a checkout counter in the next minute?

Poisson distribution.

The quality control manager of Marilyn's Cookies is inspecting a batch of chocolate chip cookies. When the production process is in control, the mean number of chocolate chip parts per cookie is 6.0. The manager is interested in analyzing the probability that any particular cookie being inspected has fewer than 10.0 chip parts. What probability distribution should be used?

Poisson distribution.

The normal distribution is ________________ in shape.

Symmetric.

Which of the following about the binomial distribution is not a true statement?

The random variable of interest is continuous.

What is one of the concepts that is true of normal distribution?

Theoretically, the mean, median , and mode are the same.

If the data values are normally distributed, the normal probability plot will follow a straight line.

True

The diameters of 100 randomly selected bolts follow a binomial distribution.

false

The largest number of possible successes in a binomial distribution is:

n

The probability that Z is less than -1.0 is ____________ the probability that Z is greater than 1.0.

the same as

Another name for the mean of a probability distribution is its expected value

true

Theoretically, the mean, median, and the mode are all equal for a normal distribution.

true