Jamie, john, and jake are on the prom committee. they are responsible for blowing up the balloons for prom night. john can blowup a balloon every 15 seconds while it takes jamie and jake 20 seconds per balloon. if 1 out of 80 balloons are found to be defected after they are inflated, identify the expression which represents the number of balloons inflated per hour.

a) 592.5x
b) 592.5 - 1/80x
c) 600x - 1/80
d) 600 - 1/80x

First, pass all the rate of inflation to ballons/hour

John: 1 b/15s * 3600 s/h = 240 b/h
Jamie: 1 b/20s * 3600 s/h = 180 b/h
Jake: 180 b/h

Then sum the rates to obtain the total rate

Total ballons per hour: 240 b/h + 180 b/h + 180b/h = 600 b/h

If it passes x hours the number of ballons inflated is 600*x

The number of ballon defective are 600*x/80

The number of ballons effectiveley inflated = 600x -600x/80 = 600x - 7.5x = 592.5x.

option A)

20.33%

Step-by-step explanation:

We have that the mean (m) is equal to 87.5, the standard deviation (sd) 6.25 and the sample size (n) = 12

They ask us for P (x <86)

For this, the first thing is to calculate z, which is given by the following equation:

z = (x - m) / (sd / (n ^ 1/2))

We have all these values, replacing we have:

z = (86 - 87.5) / (6.25 / (12 ^ 1/2))

z = -0.83

With the normal distribution table (attached), we have that at that value, the probability is:

P (z <-0.83) = 0.2033

The probability is 20.33%