## Steps and Confidence Intervals in Hypothesis Testing

This section lists four key steps in hypothesis testing and explains the close relationship between confidence intervals and significance tests.

### Significance Testing and Confidence Intervals

#### Questions

Question 1 out of 4.

The null hypothesis for a particular experiment is that the mean test score is 20. If the 99% confidence interval is (18, 24), can you reject the null hypothesis at the .01 level?

• Yes
• No

Question 2 out of 4.

Select all that apply. Which of these 95% confidence intervals for the difference between means represent a significant difference at the .05 level?

• (-4.6, -1.8)
• (-0.2, 8.1)
• (-5.1, 6.7)
• (3.0, 10.9)

Question 3 out of 4.

If a 95% confidence interval contains 0, so will the 99% confidence interval.

• True
• False

Question 4 out of 4.

Select all that apply. A person is testing whether a coin that a magician uses is biased. After analyzing the results from his coin flipping, the p value ends up being .21, so he concludes that there is no evidence that the coin is biased. Based on this information, which of these is/are possible 95% confidence intervals on the population proportion of times heads comes up?

• (.43, .55)
• (.32, .46)
• (.48, .64)
• (.76, .98)
• (.81, 1.33)