1-True or False? Suppose X and Y are independent. Then is the following TRUE or FALSE?

. ²_x-y=²_x+²_y

Group of answer choices

A-True

B-False

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2-Suppose X and Y are independent. Then is the following true or false?

_x+y=_x+_y

Group of answer choices

A-True

B-False

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3-

Which of the statements below is correct?

Group of answer choices

A-The standard deviation of X is the square root of the variance of X.

B-The standard deviation of X is the square of the variance of X.

C-None of the other choices is correct

D-The standard deviation of X is the same as the variance of X.

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4-

The mean cost of a box of Cheerios Oat Crunch is $4.00. If the price increases by 10% what is the new mean?

Group of answer choices

None of the other choices is correct

A-$4.00

B-$4.10

C-$4.40

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5-

The mean cost of a box of Cheerios Oat Crunch is $4.00 and the variance is .35. If the price increases by 25 cents a box, what is the new variance?

Group of answer choices

A-$4.25

B- 0.60

C- 0.35

D-None of the other choices is correct

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6-

Everyone at Bob's diner makes $12.00 per hour. Let X = salary of an employee at Bob's diner. What is the mean of X?

Group of answer choices

A-$0 dollars per hour

B- Not enough information to tell.

C- $12 per hour

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7- Everyone at Bob's diner makes $12.00 per hour. Let X = salary of an employee at Bob's diner. With this information, can you find the variance of X?

Group of answer choices

A- True

B- False

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8-

Let X = time waiting in line at a restaurant to get a seat. Mean of X = 20 min, Variance of X = 25

Let Y = time waiting for your food to arrive. Mean of X = 30 min, Variance of Y = 36

X and Y are correlated and the correlation is 0.80.

What is the variance of the TOTAL TIME waiting?

Group of answer choices

A-121

B- 109

C- 61

D- None of the other choices is correct

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9-

Let X = time waiting in line at a restaurant to get a seat in minutes.

What are the units of the variance of X? Choose the best answer.

Group of answer choices

A-None of the other choices is correct

B-no meaningful units

C-square minutes

D-minutes

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10-

X	1	2
p(x)	.5	.5

Y	1	2
p(y)	.9	.1

What is the mean of X+Y?

Group of answer choices

A-2.6

B-1.5

C-None of the other choices is correct

D- 3

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11-

X	1	2
p(x)	.5	.5

What is the variance of X?

Group of answer choices

A- .25

B- 1.5

C- None of the other choices is correct

D- 0.50

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12-

Suppose X = number of 1 foot long steps taken in one hour by a person working in a bank. Suppose the mean of X is 300 and the variance is 64. If you change the units from feet to inches, you multiply by 12. What is the new standard deviation?

Group of answer choices

A- 12 * 64

B- Square root of (12 x 64)

C- Square root of (12^2 x 64)

D- 12^2 x 64

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13-

If the variance of X is 10, what is the variance of 4X + 20?

Group of answer choices

A-160

B- 180

C- 60

D- 40