Question

The Sky Ranch is a supplier of aircraft parts. Included in stock are 10 altimeters that are correctly calibrated and two that are not. Three altimeters are randomly selected without replacement. Let the random variable x represent the number that are not correctly calibrated.

Answer 1

Answer: a) 0.545,b) 0.41, c) 0.045, d) not possible.

Explanation:

The Sky Ranch is a supplier of aircraft parts. Included in stock are 10 altimeters that are correctly calibrated and two that are not. Three altimeters are randomly selected without replacement. Let the random variable

x represent the number that are not correctly calibrated.

Complete the probability distribution table.

x={0,1,2,3}

P(x=0)=?

P(x=1)=?

P(x=2)=?

P(x=3)=?

Since we have given that

n = 12

number of good one = 3 from 10

number of bad one = 2

So, P(X=0)=
`(^(10)C_3* ^2C_0)/(^(12)C_3)=(120)/(220)=0.545`

P(X=1) =
`(^(10)C_2* ^2C_1)/(^(12)C_3)=(90)/(220)=0.41`

P(X=2)=
`(^(10)C_1* ^2C_2)/(^(12)C_3)=(10)/(220)=0.045`

P(X=3) is not possible.

Hence, a) 0.545,b) 0.41, c) 0.045, d) not possible.