A test score of 48.4 on a test having a mean of 66 and a standard deviation of 11. Find the z score corresponding to the given value and use the z score to determine whether the value is significant. Consider a score to be
Significant if its z score is less than -2.00 or greater than 2.00. Round the z score to the nearest tenth if necessary.
A) 1.6; not significant
B) -1.6; not significant
C) -17.6; significant
D) -1.6; significant

Question

Quizplus · Accepted Answer

The formula to calculate the z score is:

z = (x - μ) / σ

where x is the test score, μ is the mean and σ is the standard deviation.

Plugging the given values, we get:

z = (48.4 - 66) / 11
z = -1.6

Since the z score is less than -2.00 or greater than 2.00, the score is not significant. Therefore, the answer is choice B) -1.6; not significant.

A Test Score of 48