- Past evidence shows that \(7 \%\) of pears grown by a farmer are unfit for sale.
This season it is believed that the proportion of pears that are unfit for sale has decreased. To test this belief a random sample of \(n\) pears is taken. The random variable \(Y\) represents the number of pears in the sample that are unfit for sale.
- Find the smallest value of \(n\) such that \(Y = 0\) lies in the critical region for this test at a \(5 \%\) level of significance.
In the past, \(8 \%\) of the pears grown by the farmer weigh more than 180 g . This season the farmer believes the proportion of pears weighing more than 180 g has changed. She takes a random sample of 75 pears and finds that 11 of them weigh more than 180 g .
- Test, using a suitable approximation, whether there is evidence of a change in the proportion of pears weighing more than 180 g .
You should use a \(5 \%\) level of significance and state your hypotheses clearly.