7.4 Team Challenge (A)

The average price of a pound of sliced bacon is $2.02. Assume the standard deviation is $0.08. If a random sample of 40 one-pound packages is selected, find the probability that the mean of the sample will be less than $2.00.

• 0.5987

• 0.0571

• 0.9429

• 0.4013

Tags

CCSS.HSS.ID.A.4

The average age of accountants is 43 years, with a standard deviation of 5 years. If an accounting firm employs 30 accountants, find the probability that the average age of the group is greater than 44.2 years old.

• 0.9049

• 0.5948

• 0.4052

• 0.0951

Tags

CCSS.HSS.ID.A.4

A survey found that people keep their TVs an average of 4.8 years. The standard deviation is 0.89 year. If a person decides to buy a new TV, find the probability that he or she has owned their old set for more than 6 years. Assume the variable is normally distributed.

• 0.9115

• 0.5948

• 0.0885

• 0.4052

Tags

CCSS.HSS.ID.A.4

The average time it takes a group of adults to complete a certain achievement test is 46.2 minutes. The standard deviation is 8 minutes. Assume the variable is normally distributed. Find the probability that if 50 randomly selected adults take the test, the mean time it takes the group to complete the test will be between 43 and 45 minutes.

• 0.0023

• 0.1446

• 0.1423

• 0.8572

Tags

CCSS.HSS.ID.A.4