The following time series data show the number of lightning strikes in a particular county for the most recent seven months.

$\backslash$table$[[$Month$,1,2,3,4,5,6,7],[$Value$,21,10,17,9,16,20,12]]$

$($a$)$ Compute MSE using the most recent value as the forecast for the next period.

MSE $=$

What is the forecast for month $8?$

$($b$)$ Compute MSE using the average of all the data avallable as the forecast for the next period. $($Round your answer to two decimal places.$)$

MSE $=$

What is the forecast for month $8?$

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

The most recent value provides a better forecast, because its MSE is smaller than the MSE using the average of all the previous values.

The average of all the previous values provides a better forecast, because its MSE is smaller than the MSE using the most recent value.