Consider the following time series data.

$\backslash$table$[[$Month$,1,2,3,4,5,6,7],[$Value$,20,28,24,29,25,24,29]]$

$($a$)$ Compute MSE using the most recent value as the forecast for the next period. What is the forecast for month $8?$

$($b$)$ Compute MSE using the average of all the data available as the forecast for the next period. What is the forecast for month $8?$

$($c$)$ Which method appears to provide the better forecast?