hirty-five cities provided information on vacancy rates (inpercent) for local apartments in the following frequencydistribution. Vacancy Rate (in percent) Frequency 0 up to 3 7 3 upto 6 5 6 up to 9 6 9 up to 12 8 12 up to 15 9 a. Calculate theaverage vacancy rate. (Round your answer to 4 decimal places.) b.Calculate the variance and the standard deviation for this sample.(Round intermediate calculations to at least 4 decimal places andfinal answers to 2 decimal places.)
