Given sheet:

$\backslash$table$[[$Month$,$Year $1$ Sales,Year $2$ Sales,Year $3$ Sales$],[$January$,357,365,375],[$February$,357,365,375],[$September$,357,360,366],[$March$,454,485,500],[$April$,454,485,500],[$August$,454,485,500],[$October$,454,485,500],[$May$,598,610,620],[$June$,598,610,620],[$July$,598,610,620],[$November$,810,820,850],[$December$,810,820,850]]$

Please answer the following Questions using an Excel sheet only, please provide formulas in the side box also.

ANALYSIS COMPLETION NOTES:

Demonstrate the seasonality of the data:

$-$Graph all three years of data & determine which months are similar in repetition of seasonality.

$-$Sort the data by season before completing the seasonal forecasting calculations.

Calculate Seasonality Indices:

$-$Calculate the seasonal average

$-$Calculate the overall average

$-$Calculate each seasonal index.

Determine Data Trend:

$-$Calculate the total units sales for each of the three years.

$-$Determine the sales trend percentage.

Calculate Year Four Forecast for Each Month:

$-$Increase total year three sales by the expected sales increase of $1\%.$

$-$Calculate a new overall average for Year Four total sales.

$-$Multiply the new overall average times each seasonal index to determine the Year Four breakdown of sales by month.