Which option is an example of an experiment? A. Counting how many times two sixes are rolled if two dice are
rolled 100 times
B. Testing the effectiveness of a new dog training class by allowing
one group to use it and comparing results against a control group
that doesn't use it
C. Asking moms how many times a week teenagers must be
reminded to do their chores
D. Asking students in a school how much time they spend exercising

B. Testing the effectiveness of a new dog training class by allowing

one group to use it and comparing results against a control group

that doesn't use it

Step-by-step explanation:

98%

step-by-step explanation:

hello!

to begin with, we're given that on earth, a rock weighs 20 pounds, and while on jupiter, that same rock weighs 42 pounds. now, we're trying to find the weight of a rock that weighs 10.5 pounds on earth, on jupiter.

to solve this, first, set up a proportion, cross-multiply, and solve it algebraically.

setting up the proportion is the hardest and the most confusing part of the problem, but it's simple.

if on earth, the rock weighs 20 lbs, and on jupiter it weighs 42 lbs, our first part of our proportion is 20/42 lbs. the second part has to be equal to each other. this means that 10.5 has to be on the numerator of the fraction, and x, the value we're trying to find, has to be on the denominator. remember that the rock weighs 10.5 lbs on earth, and we're trying to find the weight of it on jupiter (which is x).

20/42 = 10.5/x

next, you would cross-multiply.

20x = 42(10.5)

20x = 441

now, solve it algebraically by using division.

x = 22.05 lbs

this can be rounded to 22.1 lbs.

therefore, the weight of the rock on jupiter is 22.1 lbs, the fourth choice.