The average for the statistics exam was 72 and the standard deviation was 4. Kelsey was told by the instructor that she scored 1.85 standard deviations below the mean.
poor Kelsey.
What is your question?
If you want to know Kelsey's score:
Z = (score-mean)/SD
-1.85 = (score-72)/4
To find Kelsey's score, we first need to calculate the number of standard deviations below the mean she scored. The formula for calculating the number of standard deviations below or above the mean is:
Z = (X - μ) / σ
Where:
Z is the number of standard deviations
X is the individual score
μ is the mean
σ is the standard deviation
In this case, Kelsey scored 1.85 standard deviations below the mean. So, we can rearrange the formula to find her score (X):
X = μ + (Z × σ)
Given:
μ (mean) = 72
σ (standard deviation) = 4
Z (number of standard deviations below mean) = 1.85
Substituting these values into the formula, we have:
X = 72 + (1.85 × 4)
X = 72 + 7.4
X = 79.4
Therefore, Kelsey's score on the statistics exam is 79.4.