X 12
15
17
20
22
24
25
30
P(X)
0.07 0.21 0.17 0.25 0.05 0.04 0.13 0.08
The mean of the discrete random variable X is 19.59. What is the variance
of X? Round your answer to the nearest hundredth.

Abank manager wants to encourage new customers to open accounts with principals of at least $2 comma 500. he decides to make a poster advertising a simple interest rate of 3%. what must the principal be if the bank manager also wants to advertise that one can earn $10 the first month? can the poster correctly say, "open an account of $2 comma 500 and earn at least $10 interest in 1 month! "?