New Exercise Bank Content Qu$.04-23$

The Andes Mining Company mines and ships copper ore. The company's sales manager, Juanita Valdes, has been using the movingaverage method based on the last three years of sales to forecast the demand for the next year. However, she has become dissatisfied with the inaccurate forecasts being provided by this method. The annual demands $($in tons of copper ore$)$ over the past $10$ years are $382,405,398,421,426,415,443,451,446,464.$

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a$.$ Determine the moving$-$average forecasts for the past seven years. What are MAD and MSE? Note: Round your answers to $1$ decimal place.

$$ Answer is complete but not entirely correct.

$\backslash$table$[[$MAD$,17\mathrm{.}7*$