Chapter 6. Review

Front

Identify the confidence interval used in the figure below if each shaded area is equal to 0.05.

Back

90%

Front

The symbol for the sample proportion is __________.

Back

p̂

Front

A research company wants to estimate the proportion of people who like oatmeal. They want the confidence level to be 95%. The company gets 325 people to sign up for the survey, but on the day that the survey is issued, only 250 people show up and take the survey. What happens to the confidence interval?

Back

It gets larger

Front

A sample of 400 racing cars showed that 80 cars cost over $700,000. What is the 99% confidence interval of the true proportion of cars costing over $700,000?

Back

0.148 < p < 0.252

Front

95% confidence interval of the true proportion of women in Europe who use the Internet, given 35% of 750 users were women.

Back

0.316 < p < 0.384

Front

Interpret the 99% confidence interval (0.652, 0.868) for the proportion of students who went to the homecoming game.

Back

Based on this sample, I am 99% confident that the true proportion of people who went to the homecoming game this year is between 65.2% and 86.6%.

Front

Which confidence would result in a wider interval (assuming nothing else changed), 91% or 97%?

Back

97%, z* is larger for higher confidence intervals

Front

For a sample, the 95% confidence interval is (0.202, 0.482). What is the point estimate, p̂, of this sample?

Back

0.342

Front

For a sample, the 95% confidence interval is (0.202, 0.482).
What is the margin of error of this sample?

Back

0.14

Front

A random sample of 100 WHS students found that 53 of them were in possession of a pencil. What is the p-hat for this sample?

Back

0.53