Nahab asks the students in his year group how much pocket money they get per week. The results, rounded to the nearest pound, are shown in the table. Number of Number of fx E's (x) students f 8 14 9 8 10 28 11 15 12 20 2 Totals a Complete the table. b Using the formulaff work out the variance for these data. c Work out the standard deviation for these data.

AppendixLO1