Can you assist me with this question9. The following data give the prices of seven textbooks randomly selected from a university bookstore.$89$170$104$113$56$161$147a) Find the mean for these data (input the numerical value without the dollar sign). Calculate the deviations of the data values from the mean.b) Is the sum of these deviations zero (yes or no)?c) Calculate the range (do not include unit).d) Calculate the variance.e) Calculate the standard deviationAlso Assist me with this question as wellA local gas station collected data from the dayâ€™s receipts, recording the gallons of gasoline each customer purchased. The following table lists the frequency distribution of the gallons of gas purchased by all customers on this one day at this gas station.Gallons of GasNumber of Customers4 to less than 8?788 to less than 12?4912 to less than 16?8116 to less than 2011720 to less than 24?13 What percentage of the customers purchased between 4 and 12 gallons? (do not include % sign. Round numerical value to one decimal place)