Question

on a recent test, the class mean was 8.1 with a standard deviation of 1.4. calculate the z - score (to 2 decimal places) for a person who received score of 10. z - score: blank is this an unusual (or significant) score? unusual/significant not unusual/not significant

Explanation:

Step1: Recall z - score formula

The formula for the z - score is $z=\frac{x-\mu}{\sigma}$, where $x$ is the data - point, $\mu$ is the mean, and $\sigma$ is the standard deviation.

Step2: Identify values

We are given that $\mu = 8.1$, $\sigma=1.4$, and $x = 10$.

Step3: Calculate z - score

Substitute the values into the formula: $z=\frac{10 - 8.1}{1.4}=\frac{1.9}{1.4}\approx1.36$.

Step4: Determine if it's unusual

A z - score is considered unusual if $|z|> 2$. Since $|1.36|<2$, the score is not unusual.

Answer:

z - score: 1.36
Not Unusual/Not Significant