A telemarketer for a company that sells home security systems contacts customers and find that each contact will result in no sale with probability 0.85, a R5000 sale with a probability 0.10 and a R10000 sale with probability 0.05.

4.1What is expected daily sales for the telemarketer?

4.2What is the standard deviation of her daily sales?

An investor is planning to invest in a new company. She loses 25% with a probability of 0.2 and breaks even with a probability of 0.25. If she gains, her rate of return will be either 25% or 50% with probabilities of 0.35 and 0.2 respectively.

5.1Find her expected rate of return

5.2Calculate the probability that her rate of return in this investment will be more than 10%

It is known that 90% of customers who purchase LCD Televisions will not claim against the guarantee throughout its duration. Suppose that 4 customers buy an LCD television set from a certain appliance dealer.