A manager uses this equation to predict demand for landscaping services: $F_t=7+5t.$ Over the past eight periods, demand has been as follows:

$\backslash$table$[[$Period$,t$:$,1,2,3,4,5,6,7,8],[$Demand:$,13,18,18,28,28,33,38,43]]$

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Compute the tracking signals for Periods $1-8.($Negative values should be indicated by a minus sign. Round your intermediate calculations and final answers to $3$ decimal places.$)$

$\backslash$table$[[$Period$,t,$Tracking signal$],[1,],[2,],[3,],[4,],[5,],[6,],[7,],[8,]]$