What is this series written in sigma notation 2.5 + 2.5(1.2)+2.5(1.2)^2+...+2.5(1.2)^87

Suppose there is a simple index of three stocks, stock abc, stock xyz, and stock qrs. stock abc opens on day 1 with 4000 shares at $3.15 per share. stock xyz opens on day 1 with 5000 shares at $4.30 per share. stock qrs opens on day 1 with 6000 shares at $4.60 per share. the price of stock abc on day 8 begins at $3.50. the price of stock xyz on day 8 begins at $3.90. stock qrs opens on day 8 with a price of $4.50 per share. assume that each stock has the same number of shares that it opened with on day 1. what is the rate of change of this simple index over 1 week?

Solve the following inequalities and show the solution on a number line. 3/4 (2x-7) ≤ 5

The ratio of the height of two similar cylinders is 4 to 3 what is the ratio of their volumes