Your company bids for two contracts. You believe the probability that you get contract #1 is

0.4. If you get contract #1, the probability you also get contract #2 will be 0.2, and if you do not get contract #1, the probability that you get contract #2 will be 0.1.

d. Find the expected value and standard deviation of X.

A tire manufacturer believes that the tread life of its snow tires can be described by a Normal model with a mean of 30,000 miles and a standard deviation of 2300 miles.

e) In planning a marketing strategy, a local tire dealer wants to offer a refund to any customer whose tires fail to last a certain number of miles. However, the dealer does not want to take too big of a risk. If the dealer is willing to give refunds to no more than 1 of every

25 customers, for what mileage can he guarantee these tires to last?(Round to the nearest mile as needed.)

Although controversial, some human resources departments administer standard IQ tests topotential employees. The Stanford-Binet test scores are well modelled by a Normal model with mean 100 and standard deviation 19. If the applicant pool is well modelled by this distribution, a randomly selected applicant would have what probability of scoring in the following regions? Use the 68-95-99.7 Rule to approximate the probabilities rather than using technology to find the values more precisely.

d) What is the probability of scoring below 43? ( decimal.)

Your company bids for two contracts. You believe the probability that you get contract #1 is

0.4. If you get contract #1, the probability you also get contract #2 will be 0.2, and if you do not get contract #1, the probability that you get contract #2 will be 0.1.

b) Find the expected value and standard deviation of X. (decimal)

particular IQ test is standardized to a Normal model, with a mean of 100 and a standard deviation of 11.

About what percent of people should have IQ scores between 89 and 100? Using the 68-95-99.7 rule (decimal do not round)