The Downtown Parking Authority of Tampa Florida reported the

The Downtown Parking Authority of Tampa, Florida, reported the following information for a sample of 224 customers on the number of hours cars are parked and the amount they are charged.

Find the mean and the standard deviation of the number of hours parked. (Do not round intermediate calculations. Round your final answers to 3 decimal places.)

How long is a typical customer parked? (Do not round intermediate calculations. Round your final answers to 3 decimal places.)

Find the mean and the standard deviation of the amount charged. (Do not round intermediate calculations. Round your final answers to 3 decimal places.)

Solution

a) Find the mean and the standard deviation of the number of hours parked.

Consider the table:

Thus,  
  
Mean = Sum(xf) / Sum(f) =    3.93814433 [ANSWER]

Variance = [Sum(x^2f) - Sum(xf)^2/Sum(f)]/[Sum(f)-1] =    4.752630736

Standard deviation = sqrt(Variance) =    2.18005292 [ANSWER]

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B)

Mode = 3 minutes [ANSWER]

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c)

Consider the table:

Thus,      
      
Mean = Sum(xf) / Sum(f) =    15.1185567 [ANSWER]

Variance = [Sum(x^2f) - Sum(xf)^2/Sum(f)]/[Sum(f)-1] =    65.62835853  

Standard deviation = sqrt(Variance) =    8.101133163 [ANSWER]