Question

In: Statistics and Probability

The percentage of people who recycle their old phone books is 15.8% on average. If 240...

The percentage of people who recycle their old phone books is 15.8% on average. If 240 people are randomly selected, what is the probability that more than 20% of them recycle their phone book?

Expert Solution

Solution:

Given that,

n = 240

= 0.158

1 - = 1 - 0.158 = 0.842

So,

a ) = = 0.158

= $\sqrt$ ( 1 - ) / n

= $\sqrt$ 0.158 * 0.842 /240

=0.0235

p ( > 0.20 )

= 1 - p ( < 0.20 )

= 1 - p ( - / ) < ( 0.20 - 0.158 / 0.0235 )

= 1 - p ( z < 0.042 / 0.0235 )

= 1 - p ( z < 1.79 )

Using z table

= 1 - 0.9633

= 0.0367

Probability = 0.0367

orchestra answered 3 years ago

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