served at a cafeteria is a random variable having an exponential distribution with a mean of 3 minutes. What is the probability that a person is served in less than 2

The mean points obtained in an aptitude examination is 111 points with a variance of 400.   What is the probability that the mean of the sample would be greater than 113.1 points if 79 exams are sampled? Round your answer to four decimal places.

The quality control manager at a company manufacturing company believes that the mean life of a computer is 81 months with a variance of 64. If he is incorrect what is the probability that the mean of a sample of 58 computers would differ from the population mean by less than 2.79 months round your answer to 4 decimal places

The table summarizes results from 986 pedestrian deaths that were caused by automobile accidents. Pedestrian Deaths Driver Intoxicated? Yes No Pedestrian Intoxicated? Yes No 54 80 243 609 If one of the pedestrian deaths is randomly selected, find the probability that the pedestrian was intoxicated or the driver was not intoxicated. Please enter a decimal to 4 decimal places. Probability = 0.7536 X

About 78% of all female heart transplant patients will survive for at least 3 years seventy female transplant patients are randonly selected. What is the probability that the sample proportion surving for at least 3 years will be less than 72%? Assume the sampling distribution of sample proportions is a normal distribution. The mean of the sample proportion is equal to the population proportion and the standard deviation is equal to pq/n. The probability that the sample proportion surviving for at least 3 years will be less than 72% is ____________. Round answer to four decimal places.

Assume that the square footage of a residential house in the US is normally distributed with a mean=1000 and standard deviation=150 square feet. If we select a random house what is the probability that it will be at most 1050 square feet?

The mean points obtained in an aptitude examination is 179points with a variance of 225.   What is the probability that the mean of the sample would differ from the population mean by less than 2.5 points if 77exams are sampled? Round your answer to four decimal places.

The table summarizes results from 987 pedestrian deaths that were caused by automobile accidents. Pedestrian Deaths Driver Pedestrian Intoxicated? Intoxicated? Yes No Yes 60 73 No 282 572 If one of the pedestrian deaths is randomly selected, find the probability that the pedestrian was intoxicated or the driver was intoxicated. Please enter a decimal to 4 decimal places. Probability =

A well-mixed cookie dough will produce cookies with a mean of 7 chocolate chips apiece. What is the probability of getting a cookie with no more  than 4 chips? Round to 4 decimal places

What is the probability that more than 4 accidents will occur within any given year at an intersection, where the mean number of accidents at the intersection per year is 3? what is the probability that more than 3 accidents will occur within any given year at the intersection? Give answer to 3 decimal places.