Question

After researching the possible effects of music, Elaina proposes that if people listen to faster-paced music, their pulse rates will increase more than if they listen to slower music.

Her mother listens to classic rock at a high volume for 30 minutes, her younger brother listens to classical music quietly while he sleeps at night, and her grandmother listens to
two hours of rap at a medium volume. Elaina records each person's pulse before and after listening to the music.
What is missing from Elaina's scientific investigation?

A. A testable hypothesis naming independent and dependent variables
B. An experiment that takes initial and final measurements
C. Controlled variables with only one varied independent variable
D. Experimental data that can be recorded and analyzed

Answer 1

The person above is correct. I double checked it with AI.

Answer 2

Answer: C Controlled variables with only one varied independent variable

Explanation: I believe this is the answer because she does not have only one person that listen to all of the music so the people can vary how there pulses would act to music depending on their taste and age. Elaina has a hypothesis and she did do an experiment but she did not the experiment correctly.

Hope this helps :3