Answer:
3. A matched-pairs t-test with H0 : μd = 0, HA : μd ≠ 0
Step-by-step explanation:
An investigator wants to asses the difference in mean pulses rates between sitting and standing persons in population.
The matched paired t-test is appropriate choice because the observations in the data are paired. The observations in the data are the calculated pulse rates of 50 persons while sitting and standing. For each person. sitting and standing pulse rates are measured and this indicates the before and after effect is measured. The before and after effect is measured through matched paired t test.
Also, an investigator wants to determine whether there is difference in mean pulse rates between sitting and standing in population. This indicates two tailed test. so, the hypotheses would be
Null hypotheses : μd = 0
Alternative hypotheses: μd ≠ 0.
Thus, situation indicates a matched-pairs t-test with H0 : μd = 0, HA : μd ≠ 0.