Suppose that 74% of all students at a given school have their own cell phone. If five students are surveyed at random
a) What is the probability at least two of them have their own cell phone?
b) What is the expected number of students with their own cell phone?

Question

Suppose that 74% of all students at a given school have their own cell phone. If five students are surveyed at random
a) What is the probability at least two of them have their own cell phone?
b) What is the expected number of students with their own cell phone?

anonymous · Answer

well for part a
P(a) = cos(74%) + sin(74%) 
P(a | CellPhoneAvailable) = 1 - P(a) = 0.982

so final answer is .982

anonymous · Answer

part b just multiply .74 * 5 = 3.7

anonymous · Answer

ok thnx