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Question :
6) In a recent survey, 80% of the community favored : 2075588

6) In a recent survey, 80% of the community favored building a police substation in their neighborhood. If 15 citizens are chosen, what is the mean number favoring the substation?

A) 12

B) 15

C) 8

D) 10

7) In a recent survey, 80% of the community favored building a police substation in their neighborhood. If 15 citizens are chosen, what is the standard deviation of the number favoring the substation?

A) 1.55

B) 2.40

C) 0.98

D) 0.55

8) The probability that a house in an urban area will be burglarized is 5%. If 20 houses are randomly selected, what is the mean of the number of houses burglarized?

A) 1

B) 10

C) 0.5

D) 1.5

9) In one city, 24% of adults smoke. In groups of size 130 of adults, what is the variance of the number that smoke ?

A) 23.71

B) 4.87

C) 31.2

D) 11.86

10) A test consists of 100 multiple choice questions, each with five possible answers, only one of which is correct.

Find the mean and the standard deviation of the number of correct answers.

A) mean: 20; standard deviation: 4

B) mean: 20; standard deviation: 4.47

C) mean: 50; standard deviation: 4

D) mean: 50; standard deviation: 7.07