38)An investor is considering a$15,000 investment in a start-up company. She estimates that she hasprobability 0.1 of a $10,000 loss, probability 0.05 of a $20,000 profit, probability 0.3 of a $30,000 profit, and probability 0.55 of breaking even (a profit of $0). What is the expected value of the profit?

A)$17,250 B)$9000 C)$11,000 D)$13,333

39)In a lottery, you pay $1 and pick a number from 000 to 999. If your number comes up, you win $400, which is a profit of $399. If you lose, you lose $1. Your probability of winning is 0.001. What is the expected value of your profit?

A)-$0.60 B)$0.60 C)$3.00 D)$0.399

40)The Australian sheep dog is a breed renowned for its intelligence and work ethic. It is estimated that 40% of adult Australian sheep dogs weigh 65 pounds or more. A sample of10adult dogs is studied. What is the probability that exactly 7of them weigh 65 lb or more?

A)0.785 B)0.9575 C)0.0425 D)0.2150

41)The Australian sheep dog is a breed renowned for its intelligence and work ethic. It is estimated that 25% of adult Australian sheep dogs weigh 65 pounds or more. A sample of 19 adult dogs is studied. What is the probability that no more than 3 of them weigh 65 lb or more?

A)0.7369 B)0.2631 C)0.8887 D)0.1113

42)At an airport, 84% of recent flights have arrived on time. A sample of 12 flights is studied. Find the probability that more than 10 of them were on time.

A)0.7010B)0.5945C)0.4055D)0.2990

43)In a poll conducted by a survey firm, 82% of respondents said that their jobs were sometimes or always stressful. Eight workers are chosen at random. What is the probability that less than 4 of them find their jobs stressful?

A)0.0397 B)0.9935 C)0.0065 D)0.0332

44)It is estimated that 45% of households own a riding lawn mower. A sample of 18 households is studied. What is the standard deviation of the number of households who own a riding lawn mower?

A)18 B)2.1107 C)4.455 D)8.1

45)In a poll conducted by a survey firm, 78% of respondents said that their jobs were sometimes or always stressful. Eight workers are chosen at random. What is the mean number of workers who find their job stressful?A)1.76 B)1.17 C)1.37 D)6.24

46)Compact fluorescent bulbs are more energy-efficient than incandescent bulbs, but they take longer to reach full brightness. The time it takes for a compact fluorescent bulb to reach full brightness is normally distributed with mean 30.3 seconds and standard deviation 4.9 seconds. Find and interpret the z-score for x=26.6.

A)z=0.72: the time to reach full brightness is 0.72 standard deviations below the mean.

B)z=-0.76: the time to reach full brightness is 0.76 standard deviations below the mean.

C)z=0.72: the time to reach full brightness is 0.72 standard deviations above the mean.

D)z=-0.76: the time to reach full brightness is 0.76 standard deviations above the mean