the class scores of a history test have a normal distribution with a mean μ = 79 and a standard deviation σ…

the class scores of a history test have a normal distribution with a mean μ = 79 and a standard deviation σ = 7. if opals test score was 72, which expression would she write to find the z - score of her test score?\no z = (72 - 79)/7\no z = (72 - 7)/7\no z = (79 - 72)/7\no z = (7 - 79)/7

the class scores of a history test have a normal distribution with a mean μ = 79 and a standard deviation σ = 7. if opals test score was 72, which expression would she write to find the z - score of her test score?\no z = (72 - 79)/7\no z = (72 - 7)/7\no z = (79 - 72)/7\no z = (7 - 79)/7

Answer

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

Here, $x = 72$ (Opal's score), $\mu=79$ (mean score), and $\sigma = 7$ (standard deviation).

Step3: Substitute values into formula

Substitute the values into the formula: $z=\frac{72 - 79}{7}$.

Answer:

$z=\frac{72 - 79}{7}$ (first option)