Alice wants to prove to her parents that listening to music while she does her homework will help her get better grades. She dec
ides to ask 25 of her friends if they listen to music while they do their homework and what their grades are. She finds that her friends who have high grades also listen to music while they do their homework. She tells her parents that she has proven that listening to music while doing homework will cause her grades to improve. What mistake has Alice made? A) She did not separate her friends into different groups, and she didn't apply a treatment.
B) She did not separate her friends into different groups, and she used a survey to collect data.
Explanation: First off, she did not separate her friends into different groups. Secondly, she only got information from the students who listen to music. She should've gotten information from the students who don't listen to music in order to compare her results. She needed to make the survey equal meaning that, she needed to survey the students who listen to music and the ones that don't.
We have the final part 4x/40 = 7. We can simplify this to x/10 = 7 by dividing the numerator and the denominator by 4. We then multiply both sides by 10 to get x = 70
