Scientists Hydia, Christian, and Trynatie took 100 frogs. They kept 50 of the frogs at 35 degrees C. They kept 50 of the frogs at 25 degrees C. Then they measured how fast each frog's heart beat. What was changed or different BEFORE the experiment began?

Temperature was kept as an independent variable to observe the changes in the heart beat.

Explanation:

Independent variable can be defined as the variable which can be changed to induce change in an dependent variable which is the outcome of the experiment.

According to the given situation, the temperature in which the frogs were kept changed to observe the changes in the rate of heart functioning. So, the   temperature is the independent variable which changed before the experiment began.

we need the questions , i may then you.

the answer is 1260

you spend 7 hours in school for 1 school day with 5 school days in 1 school week with 36 school weeks in a school year.

7*5*36= 1260 it's all about multiplying