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Question : The mean clotting time of blood is 7.35 seconds, with a standard deviation of 0.35 seconds : 2151857

Use the standard normal curve table to find the z-score for the given condition.

21) 4.01% of the total area is to the left of z.

A) -1.74

B) 1.70

C) -1.75

D) -1.76

22) 4.01% of the total area is to the right of z.

A) -1.75

B) 1.75

C) 1.74

D) 1.76

23) 20.05% of the total area is to the right of z.

A) -0.84

B) 0.84

C) 0.83

D) 0.82

24) 74.86% of the total area is to the left of z.

A) 0.67

B) -0.67

C) 0.68

D) 0.66

25) 25.14% of the total area is to the right of z.

A) 0.33

B) -0.68

C) 0.67

D) -0.67

26) 3.01% of the total area is to the right of z.

A) 1.89

B) -1.88

C) -1.89

D) 1.88

27) 82.89% of the total area is to the left of z.

A) 0.95

B) 0.96

C) -0.96

D) -0.95

28) 33% of the total area is to the right of z.

A) 0.74

B) -0.44

C) 0.44

D) 0.45

29) 30.15% of the total area is to the right of z.

A) 0.88

B) -0.52

C) 0.52

D) 0.53

30) 30.15% of the total area is to the left of z.

A) 0.52

B) -0.52

C) -0.53

D) -0.88

Solve the problem.

31) The mean clotting time of blood is 7.35 seconds, with a standard deviation of 0.35 seconds. What is the probability that blood clotting time will be less than 7 seconds? Assume the distribution is normal.

A) 14%

B) 16%

C) 84%

D) 15%

32) The life span of a certain insect in days is uniformly distributed over the interval [20, 36]. What is the expected life of this insect?

A) 26 days

B) 29 days

C) 28 days

D) 30 days

33) The life span of a certain insect in days is uniformly distributed over the interval [20, 36]. What is the standard deviation?

A) 4.33

B) 4.619

C) 5.774

D) 10.392

34) A company installs 5000 light bulbs. Each bulb has an average life of 500 hours with a standard deviation of 100 hours. The life of each bulb is approximated by a normal curve. Find the number of bulbs that can be expected to last less than 500 hours.

A) 3000

B) 1000

C) 2400

D) 2500

35) The life span of a certain insect in days is uniformly distributed over the interval [20, 36]. What is the probability an insect will live between the mean and one standard deviation above the mean?

A) 0.25

B) 0.79

C) 0.28

D) 0.29

36) The life span of a certain insect in days is uniformly distributed over the interval [20, 36]. What is the probability the insect will live 24 days or less?

A) 0.25

B) 0.20

C) 0.24

D) 0.75

37) A company installs 5000 light bulbs. Each bulb has an average life of 500 hours with a standard deviation of 100 hours. The life of each bulb is approximated by a normal curve. Find the number of bulbs that can be expected to last between 290 hours and 540 hours.

A) 3190

B) 1641

C) 3188

D) 1639

38) A machine fills quart soda bottles with an average of 32.3 oz per bottle, with a standard deviation of 1.2 oz. What is the probability that a filled bottle will contain less than 32 oz? Assume the distribution is normal.

A) 60%

B) 41%

C) 40%

D) 38%

39) A machine produces bolts with an average diameter of 0.30 inches and a standard deviation of 0.01 inches. What is the probability that a bolt will have a diameter greater than 0.32 inches? Assume the distribution is normal.

A) 3%

B) 98%

C) 2%

D) 1%

40) The number of new mini-vans sold by a particular salesperson during the month of March is exponentially distributed with a mean of 8. What is the probability that the salesperson will sell between 4 and 7 mini-vans in March?

A) 0.194

B) 0.190

C) 0.133

D) 0.159