Question

Find the mean and standard deviation for the set of data.

{18, 16, 6, 13, 5, 15, 24, 17, 21}
A. mean: 15; standard deviation: 6.01
B. mean: 15; standard deviation: 5.93
C. mean: 16; standard deviation: 5.93
D. mean: 16; standard deviation: 6.01

Answer 1

The mean is the sum of all numbers divided by the count of numbers. The standard deviation measures the amount of variation or dispersion in a set of values.

Let's calculate:

Mean = (18+16+6+13+5+15+24+17+21) / 9 = 135 / 9 = 15

For the standard deviation, we first find the variance (the average of the squared differences from the mean):

1. Calculate the difference from the mean for each number and square the result: (18-15)^2, (16-15)^2, etc.
2. Then calculate the average of those squared differences.
3. Finally, take the square root of that to get the standard deviation.

Doing this, we get a standard deviation of approximately 6.01.

So, the correct option is A. mean: 15; standard deviation: 6.01.