The wait times in line at a grocery store are roughly distributed normally with an average wait time of 7.6 minutes and a standard deviation of 30 seconds. What is the probability that the wait time is between 6 and 7.3 minutes

the probability that the wait time is between 6 and 7.3 minutes = 0.725

Step-by-step explanation:

Given -

Average wait time    =  7.6 minutes

Standard deviation = 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 = ]

=

                         =

[Using z table]

                         = Area to the left of z = .6 - area to the left of z = -.32

                         = .7257 - .0007 = 0.725

x =±sqrt(1/3)

step-by-step explanation:

x+4/6x=1/x

multiply each side by 6x to get rid of the fractions

6x*(x+4/6x)=1/x*6x

distribute

6x^2 +4 = 6

subtract 4 from each side

6x^2 +4-4 = 6-4

6x^2 =2

divide by 6

6x^2/6 = 2/6

x^2 = 1/3

take the square root of each side

sqrt(x^2) = ±sqrt(1/3)

x =±sqrt(1/3)

$54.99

step-by-step explanation:

$54.99 includes 500 min. if she does not exceed 500 min then her bill is $54.99