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.