Variables worksheet bryce heard that when microwave popcorn is stored at different temperatures it will have an effect on the number of kernels left after popping. to test this, he designed an experiment. he purchased 12 packets of the same kind of popcorn. he warmed 4 packets under a heat lamp to a temperature of 40 degrees celsius, he left four packets at room temperature at 20 degrees celsius, and the other four packets were placed in the freezer at -6 degrees celsius. he then microwaved each packet, for 1 minute, and recorded the data. directions: underline the control group highlight the experimental group independent variable: dependent variable: controls (constants):