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12 votes
12 votes
For the data set 7, 5, 10, 11, 12, the mean, x, is 9. What is the standard
deviation?

User Wurlitzer
by
2.9k points

1 Answer

13 votes
13 votes

Answer:

Standard Deviation is s = 2.9

Explanation:

Count =
N = 5

Mean =
x^- = 9

Variance =
s^2 = 8.5

SD Formula =
s = \sqrt (1)/(N - 1) (x_(i) - x^-)^2

Variance Formula
s^2 = ((x_(i) - x^-)^2)/(N- 1)

Step 1: Calculate the variance


= ((7-9)^2 + (5-9)^2 + (10-9)^2 + (11-9)^2 + (12 -9)^2 )/(5-1)


=(34)/(4) = 8.5

Step 2: Apply square root/SD formula


=√(8.5) = 2.9