Exam 5: Discrete Distributions

Circuit boards for wireless telephones are etched in an acid bath, in batches of 100 boards.A sample of seven boards is randomly selected from each lot for inspection.A batch contains two defective boards; and x is the number of defective boards in the sample.P(x=1)is ___.

For the Poisson distribution of a random variable lambda (λ)is 5 occurrences per ten-minute time interval.If we want to analyze the number of occurrences per hour, we must use an adjusted value for lambda equal to ___.

Variables which take on values only at certain points over a given interval are called continuous random variables.

Pinky Bauer, Chief Financial Officer of Harrison Haulers, Inc., suspects irregularities in the payroll system, and orders an inspection of a random sample of vouchers issued since January 1, 2013.A sample of ten vouchers is randomly selected, without replacement, from the population of 2,000 vouchers.Each voucher in the sample is examined for errors and the number of vouchers in the sample with errors is denoted by x.If 20% of the population of vouchers contain errors, P(x>0)is ___.

Pinky Bauer, Chief Financial Officer of Harrison Haulers, Inc., suspects irregularities in the payroll system, and orders an inspection of a random sample of vouchers issued since January 1, 2013.A sample of ten vouchers is randomly selected, without replacement, from the population of 2,000 vouchers.Each voucher in the sample is examined for errors and the number of vouchers in the sample with errors is denoted by x.If 20% of the population of vouchers contains errors, the mean value of x is ___.

If sampling is performed without replacement, the hypergeometric distribution should be used.However, the binomial may be used to approximate this if ___.

If x is the number of successes in an independent series of 10 trials, then x has a ___ distribution.

A student randomly guesses the answers to a five question true/false test.If there is a 50% chance of guessing correctly on each question, what is the probability that the student misses exactly 1 question?

The following graph is a binomial distribution with n = 6: This graph reveals that ___.

The Poisson distribution is a discrete distribution.

The number of defective parts in a lot of 25 parts is an example of ___.

Dorothy Little purchased a mailing list of 2,000 names and addresses for her mail order business, but after scanning the list she doubts the authenticity of the list.She randomly selects five names from the list for validation.If 40% of the names on the list are non-authentic, and x is the number of non-authentic names in her sample, P(x<2)is ___.

If x has a binomial distribution with p = .5, then the distribution of x is ___.

Ten policyholders file claims with CareFree Insurance.Three of these claims are fraudulent.Claims manager Earl Evans randomly selects three of the ten claims for thorough investigation.If x represents the number of fraudulent claims in Earl's sample, P(x=0)is ___.

The number of defects per 1,000 feet of extruded plastic pipe is best modelled with the ___.

For the Poisson distribution, the mean and the standard deviation are the same.

Both the Poisson and the binomial distributions are discrete distributions and both have a given number of trials.

The number of cars arriving at a toll booth in five-minute intervals is Poisson distributed with a mean of 3 cars arriving in five-minute time intervals.The probability of 5 cars arriving over a five-minute interval is ___.

A market research team compiled the following discrete probability distribution for families residing in Randolph County.In this distribution x represents the number of evenings the family dines outside their home during a week. The standard deviation of x is ___.

Dorothy Little purchased a mailing list of 2,000 names and addresses for her mail order business, but after scanning the list she doubts the authenticity of the list.She randomly selects five names from the list for validation.If 40% of the names on the list are non-authentic, and x is the number on non-authentic names in her sample, the expected (average)value of x is ___.