$.$ An analyst must decide between two different forecasting techniques for

weekly sales of inline skates: a linear trend equation and the na$$ve approach. The linear trend

equation is yt $=124+2$t$,$ and it was developed using data from periods $1$ through $10.$

Requirements: Based on data for periods $11$ through $19$ as shown below, show which of the

forecasting technique has greater accuracy?

a$)$ Perform demand forecast for periods $1219$ using the na$$ve method.

b$)$ Perform demand forecast for periods $1119$ using the given linear trend equation.

c$)$ Compute MAD $($mean absolute deviation$)$ and determine which forecast technique is

better.