Let $C(t)$ represent the cost per day to heat your home in dollars per day, where $t$ is time measured in days. Interpret the meaning of$,$ and give the units for, the following:

${\displaystyle \underset{0}{\overset{90}{}}}C(t)dt$

Below is the curve $f(x).$ What is the value of ${\displaystyle \underset{0}{\overset{7}{}}}f(x)dx?$

Use the following table to estimate ${\displaystyle \underset{10}{\overset{26}{}}}f(x)dx.$

$\backslash$table$[[x,10,14,18,22,26],[f(x),100,88,72,50,28]]$