Using the z-distribution, it is found that the 90% confidence interval for the true proportion of club members who use compost is (0.392, 0.508).
<h3>What is a confidence interval of proportions?</h3>A confidence interval of proportions is given by:
In which:
is the sample proportion.
- z is the critical value.
- n is the sample size.
In this problem, we have a 90% confidence level, hence, z is the value of Z that has a p-value of
, so the critical value is z = 1.645.
The estimate and the sample size are given by:
Hence, the bounds of the interval are:
More can be learned about the z-distribution at brainly.com/question/25890103
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