Question

Researchers have postulated that because of differences in diet, Japanese children have a lower mean blood cholesterol level than U.S. children do. Suppose that the mean level for U.S. children is known to be 170 . Let \(\mu\) represent the true mean blood cholesterol level for Japanese children. What hypotheses should the researchers test?

Short answer

The null hypothesis (H0) should be \(\mu\) = 170 and the alternative hypothesis (Ha) should be \(\mu\) < 170

Step-by-step solution

Define the null hypothesis

The null hypothesis (H0) should reflect that there's no difference in the mean blood cholesterol level compared to that of US children. So, it should be stated as: H0: \(\mu\) = 170

Define the alternative hypothesis

The alternative hypothesis (Ha) should reflect the research hypothesis, which states that the blood cholesterol level of Japanese children is lower than that of the US children. So, it should be stated as: Ha: \(\mu\) < 170