Horton Manufacturing Incorporated produces blinds and other window treatments for residential homes and offices. The owner is concerned about the maintenance costs for the production machinery because maintenance costs for the previous fiscal year were higher than he expected. The owner has asked you to assist in estimating future maintenance costs to better predict the firm$$s profitability. Together, you have determined that the best cost driver for maintenance costs is machine hours. The data from the previous fiscal year for maintenance costs and machine hours follow:

Month Maintenance Costs Machine Hours

$1$ $ $2,6951,620$

$22,7401,730$

$32,7901,745$

$42,8901,795$

$52,9251,790$

$63,0251,890$

$72,9351,810$

$82,9751,845$

$92,8501,835$

$102,6401,480$

$112,6601,690$

$122,9601,495$

Required:

$1.$ Use the high$-$low method to estimate the fixed and variable portions for maintenance costs. $($In your calculations, round "slope $($unit variable cost$)"$ to $4$ decimal places. Enter the "slope $($unit variable cost$)"$ rounded to $4$ decimal places and all other calculations, to nearest whole dollar.$)$

$2.$ Graph the data points to check for possible outliers and determine whether the points selected in requirement $1$ are representative of the data. $($Click each month and then click the graph to bring up the data coordinates. Enter the exact coordinates for each month.$)$

$3.$ Calculate the mean absolute percentage error $($MAPE$)$ for the cost equation you developed in requirement $1.($Input your final answer as a percentage rounded to $1$ decimal place $($i$.$e$.,\mathrm{.}054=5\mathrm{.}4\%).)$