In: Statistics and Probability
A bottle maker calculates that13% of his bottles are defective.
If the bottle maker is accurate, what is the probability that the proportion of defective bottles in a sample of 454 bottles would be less than 12%? Round your answer to four decimal places.
Solution
Given that,
p = 0.13
1 - p = 1-0.13=0.87
n = 454
= p =0.13
= [p ( 1 - p ) / n] = [(0.13*0.87) /454 ] = 0.0158
P( <0.12 ) =
= P[( - ) / < (0.12-0.13) / 0.0158 ]
= P(z < -0.63)
Using z table,
=0.2643
probability=0.2643