if the mean of a set of data is 23.00 and 10.00 has a z-score of -1.30, then the standard deviation must be?

Z = (score-mean)/SD, therefore

SD = (score-mean)/Z

Insert your values and solve for SD.

If the mean of a set of data is 23.00, and 10.00 has a z-score of –1.30, then the standard deviation must be:

A.
10.00
B.
9.8
C.
10.50
D.
10.20

To find the standard deviation, we need to use the z-score formula:

z = (x - μ) / σ

Where:
z = z-score
x = value in the data set
μ = mean of the data set
σ = standard deviation

In this case, we know the mean (μ) is 23.00 and a value (x) of 10.00 has a z-score of -1.30. We can rearrange the formula to solve for the standard deviation (σ):

σ = (x - μ) / z

Plugging in the values we have:

σ = (10.00 - 23.00) / -1.30

Simplifying:

σ = -13.00 / -1.30

σ = 10.00

Therefore, the standard deviation must be 10.00.