Answer
$x̅=2419$
$s=906.96$
Work Step by Step
$x_1=$ First Class Midpoint: 250
$x_2=$ Second Class Midpoint: 750
...
$x_{10}=$ Tenth Class Midpoint: 4750
$x̅=\frac{Σx_if_i}{Σf_i}=\frac{250\times5+750\times17+1250\times36+1750\times121+2250\times119+2750\times81+3250\times47+3750\times45+4250\times22+4750\times7}{500}=2419$
$s=\sqrt {\frac{Σ(x_i-x̅)^2f_i}{(Σf_i)-1}}=\sqrt {\frac{(250-2419)^2\times5+(750-2419)^2\times17+(1250-2419)^2\times36+(1750-2419)^2\times121+(2250-2419)^2\times119+(2750-2419)^2\times81+(3250-2419)^2\times47+(3750-2419)^2\times45+(4250-2419)^2\times22+(4750-2419)^2\times7}{500-1}}=906.96$
