An important step in creating confidence intervals for proportions is to check whether the success/failure conditions have been met otherwise the interval created will not be valid (i.e. we should not have created that interval)!

The following examples are estimating the proportion of the population who likes avocado.

Answer whether or not the assumptions have been met.

1. In a sample of 21 people surveyed, 8 liked avocado. Have conditions been met or not?

2. In a sample of 34 people surveyed, 8 liked avocado. Have conditions been met or not?

3. In a sample of 50 people surveyed, 36 liked avocado. Have conditions been met or not?

4. In a sample of 75 people surveyed, 15 liked avocado. Have conditions been met or not?