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Question :
21.The standard deviation the
a.variance squared
b.square root of the sum of : 1329668

21.The standard deviation is the

a.variance squared

b.square root of the sum of the deviations from the mean

c.same as the expected value

d.positive square root of the variance

22.*x* is a random variable with the probability function: f(*x*) ? *x*/6 for *x* ? 1,2 or 3. The expected value of *x* is

a.0.333

b.0.500

c.2.000

d.2.333

**Exhibit 5-1**

The following represents the probability distribution for the daily demand of microcomputers at a local store.

__ __DemandProbability

00.1

10.2

20.3

30.2

40.2

23.Refer to Exhibit 5-1. The expected daily demand is

a.1.0

b.2.2

c.2

d.4

24.Refer to Exhibit 5-1. The probability of having a demand for at least two microcomputers is

a.0.7

b.0.3

c.0.4

d.1.0

**Exhibit 5-2**

The probability distribution for the daily sales at Michael's Co. is given below.

__ ____Daily Sales ($1,000s)____Probability__

400.1

500.4

600.3

700.2

25.Refer to Exhibit 5-2. The expected daily sales are

a.$55,000

b.$56,000

c.$50,000

d.$70,000

26.Refer to Exhibit 5-2. The probability of having sales of at least $50,000 is

a.0.5

b.0.10

c.0.30

d.0.90

**Exhibit 5-3**

The probability distribution for the number of goals the Lions soccer team makes per game is given below.

__ __Number of GoalsProbability

00.05

10.15

20.35

30.30

40.15

27.Refer to Exhibit 5-3. The expected number of goals per game is

a.0

b.1

c.2

d.2.35

28.Refer to Exhibit 5-3. What is the probability that in a given game the Lions will score at least 1 goal?

a.0.20

b.0.55

c.1.0

d.0.95

29.Refer to Exhibit 5-3. What is the probability that in a given game the Lions will score less than 3 goals?

a.0.85

b.0.55

c.0.45

d.0.80

30.Refer to Exhibit 5-3. What is the probability that in a given game the Lions will score no goals?

a.0.95

b.0.85

c.0.75

d.None of the answers is correct.

**Exhibit 5-4**

A local bottling company has determined the number of machine breakdowns per month and their respective probabilities as shown below.

Number of

__ __BreakdownsProbability

00.12

10.38

20.25

30.18

40.07