Question

a missing data value from a set of data has a z - score of - 2.1. fred alrea to be μ = 43 and σ = 2. what was the missing data value? round the answ 39 41 45 47

Explanation:

Step1: Recall z-score formula

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

Step2: Rearrange to solve for $x$

Rearrange the formula to isolate $x$: $x = \mu + z\sigma$

Step3: Substitute given values

Substitute $\mu=43$, $z=-2.1$, $\sigma=2$:
$x = 43 + (-2.1)(2)$

Step4: Calculate the result

First compute $(-2.1)(2) = -4.2$, then add to 43:
$x = 43 - 4.2 = 38.8$
Round to the nearest whole number: $x \approx 39$

Answer:

A. 39