Answer:
the probability that the wait time is between 6 and 7.3 minutes = 0.725
Step-by-step explanation:
Given -
Average wait time [tex](\nu)[/tex] = 7.6 minutes
Standard deviation [tex](\sigma)[/tex] = 30 second = .5 minute
Let X be the wait times in line at a grocery store
the probability that the wait time is between 6 and 7.3 minutes
[ Put z = [tex]\frac{X - \nu }{\sigma}[/tex] ]
[tex]P (7.3> X>6 )[/tex] = [tex]P (\frac{7.3 - 7.6}{.5}> Z>\frac{6 - 7.6 }{.5} )[/tex]
= [tex](.6> Z> -3.2 )[/tex]
[Using z table]
= Area to the left of z = .6 - area to the left of z = -.32
= .7257 - .0007 = 0.725
