A study of wait times at Texas roadhouse a random sample of 63 patrons were asked how long their wait times was. The study concluded that their wait times were normally distributed with a mean wait time of 28.4 minutes and a standard deviation of 3.6 minutes. what range of values represents the middle 95% of the data?



Answer :

Let's use Probability mass function:

[tex]P(X)=\frac{1}{\sigma\sqrt[]{2\pi}}e^{-\frac{(x-\mu)^2}{2\sigma^{^2}}}[/tex]

Where:

[tex]\begin{gathered} \sigma=\text{ Standard deviation = 3.6} \\ \mu=\operatorname{mean}=28.4 \end{gathered}[/tex]

[tex]P(X)=(0,22.3)[/tex]