How could you reword these research hypotheses to null hypotheses?

a. Smoking during pregnancy increase the risk of a child being born prematurely.

b. Regular exercises in older adults decreases blood pressure levels.

a. Ho: Smoking during pregnancy is not related to premature birth.

b. Ho: Exercise in older adults is not related to blood pressure levels.

To reword the research hypotheses to null hypotheses, you would need to state them as a statement of no effect or no relationship. Here are the reworded null hypotheses for the given research hypotheses:

a. There is no relationship between smoking during pregnancy and the risk of a child being born prematurely.

b. There is no effect of regular exercises in older adults on blood pressure levels.