Yuri computes the mean and standard deviation for the sample data set 12, 14, 9, and 21. he finds the mean is 14. his steps for finding the standard deviation are below. what is the first error he made in computing the standard deviation?
a. yuri failed to find the difference between each data point and the mean.
b. yuri divided by n instead of n -1.
c. yuri did not subtract 9 - 14 correctly.
d. yuri failed to square -2 correctly.

Option B.

Step-by-step explanation:

Consider the below figure attached with this question.

Formula for standard deviation of a sample:

where, n is sample size and is sample mean.

The sample data set is 12, 14, 9, and 21.

The mean is 14.

So, the sample standard deviation is

According to Yuri,

Yuri divides the sum of square of difference between each data point and the mean by n instead of n -1.

Therefore, the correct option is B.

false

step-by-step explanation:

i looked it up

c

step-by-step explanation:

it isn't d, because the interquartile range is from 27-57. and the interquartile range is basically half the data, it's pretty obvious.

it isn't b, because like i said earlier, the interquartile range is from 27-57. 57-27 is 30. the real range has to be longer

not a either. although it looks like it, 3/4 of the data is not greater than 27. but if c is wrong than this should be correct

the correct answer is c, because 13 is the point in which the plot starts