Question

Test scores are normally distributed with a mean of 86 and a standard devotion of 2.2 what percent scored between 83.8 and 92.6? What percent scored below 83.8?

Answer 1

Z- Score formula is:

`\begin{gathered} Z=(x-\mu)/(\sigma) \\ Z\text{ is the z-score (Standard score)} \\ X\text{ is the value to be standardized} \\ \mu\text{ is the mean} \\ \sigma\text{ is the standard deviation} \end{gathered}`

Here, the mean is 86, while the standard deviation is 2.2

Percent between 83.8 and 92.6 is;

`P((83.8-86)/(2.2)<strong>The percent between 83.8 and 92.6 = 0.83999</strong><p></p>[tex]P(Z<-1)=\text{ 0.15866}`

Percent score below 83.8 is 0.15866