At the end of April, the average monthly use of an ATM was 320 customers and the

Question:

At the end of April, the average monthly use of an ATM was 320 customers and the trend was +100 customers per month. The actual use rates for May, June, and July are 880, 910, and 990, respectively. Use trend-adjusted exponential smoothing with α = 0.3 and β = 0.2 to forecast the ATM usage for June, July, and August.