Question

What is the standard deviation of the given data set? Round to the nearest tenth.



5, 10, 7, 12, 0, 20, 15, 22, 8, 2
A


6

B


6.89

C


6.892

D


6.9

Answer 1

To calculate the standard deviation, we first need to find the mean of the data set.

Mean = (5 + 10 + 7 + 12 + 0 + 20 + 15 + 22 + 8 + 2) / 10 = 10.1

Next, we subtract the mean from each number in the data set, square the result, and then find the mean of those squared differences.

(5 - 10.1)^2 = 26.01
(10 - 10.1)^2 = 0.01
(7 - 10.1)^2 = 9.61
(12 - 10.1)^2 = 3.61
(0 - 10.1)^2 = 102.01
(20 - 10.1)^2 = 98.01
(15 - 10.1)^2 = 23.41
(22 - 10.1)^2 = 141.61
(8 - 10.1)^2 = 4.41
(2 - 10.1)^2 = 65.61

Mean of squared differences = (26.01 + 0.01 + 9.61 + 3.61 + 102.01 + 98.01 + 23.41 + 141.61 + 4.41 + 65.61) / 10 = 47.2

Finally, we take the square root of the mean of squared differences to get the standard deviation.

Standard deviation = √47.2 ≈ 6.9

Therefore, the correct answer is D. 6.9.

Answer 2

Which is an example of qualitative data?


A


the number of textbooks in a classroom

B


the condition of the textbooks in a classroom

C


the ID numbers of the textbooks in a classroom

D


the number of pencil marks in the textbooks in a classroom

Answer 3

B
the condition of the textbooks in a classroom