Question

Solar-heat installations successfully reduce the utility bill 60% of the time. What is the probability that at least 9 out of 10 solar-heat installations are successful and will reduce the utility bill? a. 0.0464 b. 0.9432 c. 0.0403 d. 0.8429

Answer 1

Answer:

P=0.04635.

Step-by-step explanation:

We know that solar-heat installations successfully reduce the utility bill 60% of the time. We calculate the probability that at least 9 out of 10 solar-heat installations are successful and will reduce the utility bill.

We know that: 60%=0.6=p and n=10.

We have a binomial distribution: X : (10, 0.6).

We use the formula to calculate the probability:

$\boxed{ P(X=x)=\left( \begin{array}{c} n \\ x \end{array} \right) \cdot p^x \cdot (1-p)^{n-x}}$

We get:

$P(X\geq 9)=1-P(X$

Therefore, the probability is P=0.04635.