p1q1

Sophie Johnson, CFO of Neonte, suspects irregularities in the payroll system, and orders an inspection of a random sample of vouchers issued last year.A sample of ten vouchers is randomly selected, without replacement, from the population of 1800 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 25% of the population of vouchers contain errors, P(x = 0) is:

p1q5

If x, the time (in minutes) to complete an change job at certain auto service station, is uniformly distributed over the interval 20 to 56, then the probability that an oil change job is completed in 33 to 35 minutes is:

p1q7

A carload of steel rods has arrived at BlueCon LLC. The car contains 50,000 rods. Ruby Brown, manager of Quality Assurance, directs her crew measure the lengths of 86 randomly selected rods. If the population of rods have a mean length of 120 inches and a standard deviation of 0.1 inch, the probability that the sample has a mean less than 119.985 inches is:

P2-q1

A large industrial firm allows a discount on any invoice that is paid within 30 days. Of all invoices, 20% receive the discount. In a company audit, 15 invoices are sampled at random. The mean (average) value of the number of the 15 sampled invoices that receive discount is:

p2-q3

Suppose that during a given week, 20 new customers have signed up for a specialized service your company provides. Eight of these new customers are financial services companies, and the remaining twelve are automotive firms. If a random sample of 5 of these new customers will be selected for a study of customer satisfaction in one month, what is the probability that 3 of the selected customers are financial services firms?

p2-q4

Canterbury Tire LLC has established that the useful life of a particular brand of its automobile tires is normally distributed with a mean of 44000 miles and a standard deviation of 6200 miles. What is the probability that a randomly selected tire of this brand has a life of at least 50,000 miles?

p2q6

6)	Suppose the population of college dataset shows the annual parking fee per student is $112 with a standard deviation of $15. If a random sample of size 49 is drawn from the population, the probability of drawing a sample with a sample mean between $100 and $115 is:

p2q7

Suppose the salaries of Starbucks employees are normally distributed with a mean of $32,000 standard deviation of $12100. Suppose we take samples of size 21 employees. Find the probability that the sample mean salary will exceed $35,000.