1. ## Kyla's Test

The probability that Kyla will score above a 90 on a mathematics test is . What is the probability that she will score above a 90 on three of the four tests this quarter?

2. Originally Posted by magentarita
The probability that Kyla will score above a 90 on a mathematics test is p . What is the probability that she will score above a 90 on three of the four tests this quarter?
A necessary piece of information is missing. The red p marks the spot.

The answer will be $\displaystyle {4 \choose 3} p^3 (1 - p) = 4 p^3 (1 - p)$ where p is the value you haven't given.

3. ## ok............

Originally Posted by mr fantastic
A necessary piece of information is missing. The red p marks the spot.

The answer will be $\displaystyle {4 \choose 3} p^3 (1 - p) = 4 p^3 (1 - p)$ where p is the value you haven't given.
Thank you very much.