Answer:
At least 37.74% of the procedures takes between 97.6 and 125.6 minutes
Step-by-step explanation:
The percentage is the area of the standard normal distribution curve between the values 97.6 and 125.6
The standard normal variate of the given data is found as
[tex]Z=\frac{X-\overline{X}}{\sigma }[/tex]
Thus for the given values Z is calculated as under
[tex]Z_1=\frac{97.6-111.6}{2.8}=-5[/tex]
Similarly for the other value we have
[tex]Z_2=\frac{125.6-111.6}{2.8}=5[/tex]
Thus the area between the calculated values can be found from standard normal distribution table to be 37.74%
