A set of 50 data values has a mean of 15 and a variance of 25. Find the standard score of a data value = 20
Z = (score-mean)/SD
SD^2 = variance
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I apologize...thank you....so is it
A data point of 20 is one standard deviation above the mean of 15, so the standard or "z" score is 1.0
To find the standard score of a data value, also known as the z-score, you can use the formula:
z = (x - μ) / σ
Where:
- x is the data value
- μ is the mean of the data set
- σ is the standard deviation of the data set
In this case, since the variance is provided, we can calculate the standard deviation by taking the square root of the variance.
σ = √variance
= √25
= 5
Now, we can use the formula:
z = (x - μ) / σ
z = (20 - 15) / 5
z = 5 / 5
z = 1
Therefore, the standard score (z-score) of the data value 20 is 1.
Please note that in order to find the mean and variance of the data set, additional information or calculations may be required.