## Wolfboy 3 years ago A local weather forecaster is accurate 85% of the time when predicting precipitation for the day. What is the probability that she will make correct precipitation predictions 4 days in a row? about 54% about 53% about 52% about 47%

1. kropot72

The probability of being correct on one day is 0.85. The forecast for each day is separate and independent of the other daily forecasts. Therefore the compound event, correct predictions 4 days in a row, is the product of the separate probabilities of being correct for each of the 4 days. P(correct 4 days) = 0.85 * 0.85 * 0.85 * 0.85. Can you calculate the probability and convert to a percentage ?

2. Wolfboy

ehh i might need some help with that

3. kropot72

Have you got a calculator handy?

4. Wolfboy

Yus

5. Wolfboy

*yes

6. kropot72

Multiply 0.85 by 0.85. Then multiply the answer by 0.85. Then multiply that answer by 0.85. What do you get?

7. Wolfboy

.52200625

8. kropot72

Correct. To convert to a percentage multiply 0.52200625 by 100. Then choose the answer that is closest to the result.

9. Wolfboy

Tank you lots!

10. kropot72

You're welcome :)