In many respects, investing in the stock market is just another form of gambling: you pay money for the stocks, and when you sell them at some point, you can gain money, lose money, or break even. Use what you learned about expected value to answer the questions about buying and selling stock.

The Bui family decides to invest their

$4000

tax refund in the stock market for one year. An analyst suggests that they choose between two stocks. A computer analysis of past performance predicts that if they invest in RZ Electronics, there's a

20%

chance they'll make a profit of

$1200

,a

20%

chance they'll make

$350

,and a

60%

chance they'll lose

$2000

.For Jackson Builders, there's a

60%

chance they'll make

$800

,and a

40%

chance they'll lose

$300

.

Part 1 of 2

(a)Without doing any calculations, which sounds like the better investment to you?

Without doing any calculations, (Choose one) sounds like the better investment.

Part:1 / 2

1 of 2 Parts Complete

Part 2 of 2

(b)Find the expected value of each investment. Round your answers to the nearest cent.

The expected value of the RZ Electronics investment is dollars. The expected value of the Jackson Builders investment is dollars.

Coronary bypass surgery:A healthcare research agency reported that

55%

of people who had coronary bypass surgery in

2008

were over the age of

65.

Thirteen coronary bypass patients are sampled.

Part 1 of 2

(a) What is the mean number of people over the age of

65

in a sample of

13

coronary bypass patients? Round the answer to two decimal places.

The mean number of people over the age of 65 is .

Part 2 of 2

(b) What is the standard deviation of the number of people over the age of

65

in a sample of

13

coronary bypass patients? Round the answer to four decimal places.

The standard deviation of the number of people over the age of 65 is .

Your flight has been delayed:At Denver International Airport,

75%

of recent flights have arrived on time. A sample of

14

flights is studied. Round the probabilities to at least four decimal places.

Part 1 of 4

(a)Find the probability that all

14

of the flights were on time.

The probability that all 14 of the flights were on time is .

Part 2 of 4

(b)Find the probability that exactly

12

of the flights were on time.

The probability that exactly 12 of the flights were on time is .

Part 3 of 4

(c)Find the probability that

12

or more of the flights were on time.

The probability that 12 or more of the flights were on time is .

Part:3 / 4

3 of 4 Parts Complete

Part 4 of 4

(d)Would it be unusual for

13

or more of the flights to be on time? Use a cutoff of

0.05

.

It (Choose one) be unusual for

13

or more of the flights to be on time since the probability is

.