question 1

Assume that the test scores from a college admissions test are normally distributed, with a mean of 485 and a standard deviation of 86.

What fraction of students taking the test score between 325 and 645?

a) 0.8968

b) 0.8664

c) 0.8384

d) 0.9371

John receives a score of 590. What fraction of the people taking the test score higher?

a) 0.1111

b) 0.0668

c) 0.0735

d) 0.0901

A certain university admits only those who score in the top 10 percent. What is the benchmark test score for admitting the students?

a) 575

b) 572

c) 595

d) 558

question 2

A car leasing company is considering offering a special service contract that will cover the total cost of any service work required on leased vehicles. From experience, the company manager estimates that yearly service costs are approximately normally distributed, with a mean of $420 and a standard deviation of $75.

If the company offers the service contract to customers for a yearly charge of $600, what is the probability that any one customer's service costs will exceed the contract price of $600?

a) 0.0082

b) 0.1630

c) 0.1516

d) 0.1423

question 3

Weight of newborn babies in the United States is normally distributed, with a standard deviation of 510 grams. The fraction of newborn babies who weight less than 2200 grams is 0.0548. What fraction weight more than 4000 grams?

a) 0.0808

b) 0.0901

c) 0.1003

d) 0.0268

question 4

The average annual amount American households spend for transportation is $9,850. Assume the amount spent is normally distributed.

Suppose you learn that 5% of American households spend less than $4,800 for daily transportation. What is the standard deviation of the amount spent?

a) $4,237

b) $3,945

c) $3,828

d) $3,079

What fraction of households spend between $4,850 and $14,850?

a) 0.8948

b) 0.6912

c) 0.7230

d) 0.7960