a$.$ In cell $B20,$ enter a formula using the COUNTIF function to count the number of substation agreements sold. Use the list of equipment codes $($range D$6$:D$14)$ as the range and the code for substations $($cell I$9)$ as the criteria in your formula.

b$.$ In cell B$21,$ enter a formula using the AVERAGEIF function to find the average sale price of a substation agreement. Use the list of equipment codes as the range, the code for substations as the criteria, and the sale prices $($range $G6$:$G14$ as the range to average in your formula.

c$.$ In cell B$22,$ use the SUMIF function to find the total sale price of substation agreements. Use the list of equipment codes as the range, the code for substations as the criteria, and the sale prices as the range to sum in your formula.