$44.$ Stated as a percentage rounded to two $[2]$ decimal places, what is the approximate numerical value of the amount of the variation in monthly income that accounted for by the regression performed in part $42?$ a$.89\mathrm{.}45\%$ b$.90\mathrm{.}18\%$ c$.2\mathrm{.}15\%$ d$.48\mathrm{.}67\%$e$.80\mathrm{.}01\%$ QUESTION $4545.$ According to your regression analysis performed for part $42,$ what is the approximate average rate of change of monthly income? $($Round to two $(2]$ decima! places.$)$ a$.2\mathrm{.}15\%$ per month. b$.$ $$80\mathrm{.}01$ per month$\mathrm{.}0$ c$.$ $$48\mathrm{.}55$ per month. d$.89\mathrm{.}45\%$ per month. e$.$ $$2146\mathrm{.}70$ per month.Monthly income in thousands of dollars $($$K$)$ at the Acme Law Firm for the $13-$month period from January this year to January next year is listed in the table below. $($For parts $39$ to $47,$ download the Excel file "Exam $2$ time series data" in the "Exam $2$ Excel forecasting file" link in the "Assessments" in the Navigation bar of the Bb course website. Save your completed Excel file containing your calculations for parts $39$ to $47$ for later uploading to Bb$.)$

$\backslash$table$[[$Month$,$Income $($$K$)],[$Jan$,51\mathrm{.}8],[$Feb$,55\mathrm{.}5],[$Mar$,54\mathrm{.}7],[$Apr$,57\mathrm{.}1],[$May$,50\mathrm{.}6],[$Jun$,68\mathrm{.}2],[$Jul$,66\mathrm{.}4],[$Aug$,59\mathrm{.}3],[$Sep$,67\mathrm{.}2],[$Oct$,69\mathrm{.}8],[$Nov$,77\mathrm{.}6],[$Dec$,74\mathrm{.}4],[$Jan$,75\mathrm{.}5]]$