Historical demand for a product is as follows: April DEMAND 60 May 55 June 75 July August September 60 80 75 a. Using a simple four-month moving average, calculate a forecast for October. (Round your answer to 2 decimal places.) Forecast for October b. Using single exponential smoothing with a = 0.2 and a September forecast = 65, calculate a forecast for October. (Round your answer to 1 decimal place.) Forecast for October c. Using simple linear regression, calculate the trend line for the historical data. Say the X axis is April = 1, May = 2, and so on, while the Y axis is demand. (Round your intercept value to the nearest whole number and slope value to 2 decimal places.) Y = + t d.Calculate a forecast for October using your regression formula. (Round your answer to 2 decimal places.) Forecast for October