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) -17.6 ; significant
B) -1.6 ; significant
C) -1.6 ; not significant
D) 1.6 ; not significant

Question

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)  -17.6 ; significant
B)  -1.6 ; significant
C)  -1.6 ; not significant
D)  1.6 ; not significant

Quizplus · Accepted Answer

The z score is calculated using the formula $z = \frac{(X - \mu)}{\sigma}$, where $X$ is the score, $\mu$ is the mean, and $\sigma$ is the standard deviation. Substituting the given values, $z = \frac{(48.4 - 66)}{11} = -1.6$. Since $-2.00 < z < 2.00$, the score is not considered significant.

A Test Score of 48