Mei wants to study whether heart rate increases more during certain exercises than during others. she designs an experiment to test the heart rates of classmates in the morning and in the evening for three days, immediately after doing jumping jacks, doing push-ups, or running in place. what is the dependent variable in this experiment?

Cathy hypothesized that corn would not grow in mud. to test this hypothesis, she took corn kernels and placed 5 in mud, 3 in soil, and 2 in water. to her surprise, the kernels in the mud grew faster than the kernels in the soil. what error might have caused these unexpected results? a. wrong hypothesis b. not enough variables c. undefined control d. too many variables