the class scores of a history test have a normal distribution with a mean \\( \\mu = 79 \\) and a standard…
the class scores of a history test have a normal distribution with a mean \\( \\mu = 79 \\) and a standard deviation \\( \\sigma = 7 \\). if opal’s test score was 72, which expression would she write to find the z - score of her test score?\\( \\bigcirc \\ z = \\frac{72 - 79}{7} \\)\\( \\bigcirc \\ z = \\frac{72 - 7}{7} \\)\\( \\bigcirc \\ z = \\frac{79 - 72}{7} \\)\\( \\bigcirc \\ z = \\frac{7 - 79}{7} \\)
Answer
Explanation:
Step1: Recall z - score formula
The formula for calculating the z - score is (z=\frac{x - \mu}{\sigma}), where (x) is the raw score, (\mu) is the mean, and (\sigma) is the standard deviation.
Step2: Identify values
Here, (x = 72), (\mu=79), and (\sigma = 7).
Step3: Substitute values into formula
Substituting these values into the z - score formula, we get (z=\frac{72 - 79}{7}).