Question

A group of researchers was interested in looking at the change of heart rate when participants engage in a step-up exercise. Step-up exercise is where a person starts with both feet on the ground and then steps up onto a step. In this study, the step is either 5.75 inches off the ground or 11.5 inches off the ground. Subjects were randomly assigned to a step-up exercise on either a 5.75-inch step or an 11.5-inch step. The change in heart rate between just before exercise and after 3 minutes of exercise was recorded for each person. Summary information is given below (in beats per minute (BPM)).

The researchers wondered if the exercises on the higher step (11.5 inch) would increase heart rates more, on average, than the lower step (5.75 inch).

             5.75-inch step        11.5-inch step

                        Sample size         15 15

                        Sample mean             19.4 BPM    35.4 BPM

                        Sample standard deviation 12.7BPM 18.3 BPM

What is the response variable?

Group of answer choices

whether or not heart rate is more using the 11.5-inch step compared to the 5.75-inch step

the type of step used (5.75-inch or 11.5-inch step)

the number of people in each of the comparison groups

the change in heart rate for each individual from just before exercising to three minutes after exercising

heart rate after exercise

A group of researchers was interested in looking at the change of heart rate when participants engage in a step-up exercise. Step-up exercise is where a person starts with both feet on the ground and then steps up onto a step. In this study, the step is either 5.75 inches off the ground or 11.5 inches off the ground. Subjects were randomly assigned to a step-up exercise on either a 5.75-inch step or an 11.5-inch step. The change in heart rate between just before exercise and after 3 minutes of exercise was recorded for each person. Summary information is given below (in beats per minute (BPM)).

The researchers wondered if the exercises on the higher step (11.5 inch) would increase heart rates more, on average, than the lower step (5.75 inch).

             5.75-inch step        11.5-inch step

                        Sample size         15 15

                        Sample mean             19.4 BPM    35.4 BPM

                        Sample standard deviation 12.7BPM 18.3 BPM

What kind of study was performed?

Group of answer choices

prospective observational study

retrospective observational study

simple random sample

stratified random sample

completely randomized experiment

A group of researchers was interested in looking at the change of heart rate when participants engage in a step-up exercise. Step-up exercise is where a person starts with both feet on the ground and then steps up onto a step. In this study, the step is either 5.75 inches off the ground or 11.5 inches off the ground. Subjects were randomly assigned to a step-up exercise on either a 5.75-inch step or an 11.5-inch step. The change in heart rate between just before exercise and after 3 minutes of exercise was recorded for each person. Summary information is given below (in beats per minute (BPM)).

The researchers wondered if the exercises on the higher step (11.5 inch) would increase heart rates more, on average, than the lower step (5.75 inch).

             5.75-inch step        11.5-inch step

                        Sample size         15 15

                        Sample mean             19.4 BPM    35.4 BPM

                        Sample standard deviation 12.7BPM 18.3 BPM

What is the response variable?

Group of answer choices

whether or not heart rate is more using the 11.5-inch step compared to the 5.75-inch step

the type of step used (5.75-inch or 11.5-inch step)

the number of people in each of the comparison groups

the change in heart rate for each individual from just before exercising to three minutes after exercising

heart rate after exercise

Answer 1

1] Response Variable is the change in heart rate for each individual from just before exercising to three minutes after exercising.

2] This is completely randomized experiment because treatments are randomly assigned to the groups.