It has been estimated that only about 40% of California residents have adequate earthquake supplies. Suppose we are interested in the number of California residents we must survey until we find a resident who does not have adequate earthquake supplies

How many California residents do you expect to need to survey until you find a California resident who does not have adequate earthquake supplies?

Thank you for the opportunity to help you with your question!

W
is the number of California resident and has geometric distribution with p =probability of not having supplies = 1-0.4 = 0.6

Hence P(W=x)
= (0.4)^{n-1}0.6 for n =
1,2,3…….

For example, P(W≥3)
= 1-P(W≤2) = 1-W(1)-W(2) = 1- 0.6-0.4(0.6) = 0.7

which is the probability of at
least 3 California residents until we find a California resident who does not
have adequate earthquake supplies ** P/S: Please remember to give me a review later on once the answer is correct. I would be highly appreciate it. Thank you. **