Question

Perfect Solo Problem: Clara Nett plays a musical
solo. She is quite good and guesses that her
probability of playing any one note right is 99%.
The solo has 60 notes.

a. Find the probability that

i. She plays every note right
ii. She makes exactly one mistake
iii. She makes exactly two mistakes
iv. She makes at least two mistakes
v. She makes more than two mistakes
b. What must be Clara’s probability of playing
any one note right if she wants to have a 95%
probability of playing all 60 notes right?

Answer 1

R -- right = .99
W -- wrong = .01

prob(all correct) = C(60,60) (.99^60) (.01)^0)
= .00^60 = ...

prob(59right,1wrong)
= C(60,59)(.99^59)(.01^1) = ....

Prob(58right,2wrong) = ....... ** (see above and adjust)

prob(at least 2 wrong) = 1 - **

you try the others.