7. The Relationship between Confidence Intervals and Tests of Significance
d. explain a decision rule, the power of a test, and the relation between confidence intervals and hypothesis tests;
What is a confidence interval?
A confidence interval is a range of values within which it is believed that a certain unknown population parameter (often the mean) will fall with a certain degree of confidence. The percentage of confidence is denoted (1 - \alpha)%
.
What is a test of significance?
A test of significance is a test to ascertain whether or not the value of an unknown population parameter is as stated by an individual or institution. This test is carried out at a significance level of \alpha
, which determines the size of the rejection region.
What is a test of significance testing for? What is the math formula? - We are testing to see the likelihood that the z-value will be less than the test statistic. - \(\mu_0 < \bar{x} - \frac{(z_{a/2})(\sigma)}{\sqrt{n}}\)
When conducting a significance test and the confidence interval contains the value of the unknown population parameter as hypothesized in the null hypothesis (H_0
), is the null hypothesis rejected or not?
Not rejected
Given the following info, is the p-value > or < 0.05?
H_0:\mu = 50
, H_a:\mu != 50
, normal population with \sigma = 6
. Standard confidence interval for the mean is (51.3, 54.7).
Source:
CFA
Graph:
- 115.020.60 Reading 11 - Hypothesis Testing to 115.020.60.07 Reading 11 - 7. The Relationship between Confidence Intervals and Tests of Significance