Consider the following time series data.

$\backslash$table$[[$Week$,1,2,3,4,5,6],[$Value$,19,14,15,10,17,15]]$

Using the naive method $($most recent value$)$ as the forecast for the next week, compute the following measures of forecast accuracy.

$($a$)$ Mean absolute error

If required, round your answer to one decimal place.

$($b$)$ Mean squared error

If required, round your answer to one decimal place.

$($c$)$ Mean absolute percentage error

If required, round your intermediate calculations and final answer to two decimal places.

$($d$)$ What is the forecast for week $7?$