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

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:

We get:

Therefore, the probability is P=0.04635.

225x²+4=0

225x²=0-4

225x²=-4

x²=-4/225

x=±√-4/225