What is the third quartile of the following data set? 15, 18, 20, 21, 23, 24, 26, 29, 34, 37, 40

Ican figure out 20 shares multiply by $117.98 =2359.6920 shares multiply by $124.32=2486.40then take 40 shares multiply by $128.48=5139.20after that i'm lost any be greatly appreciated.

Find the commission on a $590.00 sale if the commission is 15%.

Find the volume of the solid obtained by rotating the region enclosed by the curves y=1x and y=7^-x about the x-axis. (use symbolic notation and fractions where needed.) volume =