Question

In a random sample of 170 people, it is found that the proportion who prefer chocolate to vanilla ice cream is 0.72 with a margin of error of 0.03 at a 90% level of confidence. (a) Express this confidence interval in interval form. Round your answers to two decimal places.

Answer 1

To create a confidence interval, subtract and add the margin of error to the sample proportion.

Step-by-step explanation:

To create a confidence interval, you need the sample proportion, margin of error, and the level of confidence. In this case, the sample proportion is 0.72, the margin of error is 0.03, and the level of confidence is 90%. To calculate the confidence interval, you add and subtract the margin of error from the sample proportion. So, the confidence interval is [0.69, 0.75].