Iwill mark you as brainlinest for correct !

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.

Acircle has a radius of 5/6 units and is centered at (3.6, 7.8) write the equation of this circle

Given the equation f(x)=a(b)x where the initial value is 40 and the growth rate is 20% what is f(4)