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Find the mean and the standard deviation of the data set {2, 3, 6, 7, 6}.

A. The mean is 4.8 and the standard deviation is about 3.76.
B. The mean is 24 and the standard deviation is about 4.16.
C. The mean is 4.8 and the standard deviation is about 1.94.
D. The mean is 5.2 and the standard deviation is about 2.04.

1 Answer

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Answer: the mean of the data set is 4.8, and the standard deviation is about 1.94. The answer is C.

Explanation:

To find the mean and the standard deviation of the data set {2, 3, 6, 7, 6}, we can use the following formulas:

Mean = (sum of all data values) / (number of data values)

Standard deviation = sqrt[(sum of squared differences from the mean) / (number of data values)]

First, we need to find the mean:

Mean = (2 + 3 + 6 + 7 + 6) / 5

Mean = 4.8

Next, we can find the standard deviation:

Calculate the differences between each data value and the mean:

2 - 4.8 = -2.8

3 - 4.8 = -1.8

6 - 4.8 = 1.2

7 - 4.8 = 2.2

6 - 4.8 = 1.2

Square each difference:

(-2.8)^2 = 7.84

(-1.8)^2 = 3.24

(1.2)^2 = 1.44

(2.2)^2 = 4.84

(1.2)^2 = 1.44

Find the sum of the squared differences:

7.84 + 3.24 + 1.44 + 4.84 + 1.44 = 18.80

Divide the sum by the number of data values:

18.80 / 5 = 3.76

Take the square root:

sqrt(3.76) = 1.94 (rounded to two decimal places)

Therefore, the mean of the data set is 4.8, and the standard deviation is about 1.94. The answer is C.

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