Chapter 8.2, Problem 32E

To determine

To explain whether the conditions for calculating a confidence interval for the population proportion.

Answer to Problem 32E

The condition of random sample and large count is not met.

Explanation of Solution

Given:

  $n=98$

The population of all whelks.

The whelk eggs were only selected from the coast of Oregon. So, the whelk in the sample are most likely not representative for all the whelk eggs which cannot be say random sample. Therefore, condition of random sample not satisfied.

The sample should be less than 10% of the population. Here, 98 whelks are less than 10% of the all whelks. Hence, this condition met.

The last condition is, number of success and failure must be $\ge 10$ . Therefore, number of successes =9<10 and number failures = 98-9=89 $\ge 10$ which is not met. Hence, all the conditions of confidence interval are not met.