originally a rectangle was twice as long as it was wide. when 4m were added to its length and 3m were added to it's width. the resulting rectangle had an area of 600 meters squared. Find the dimensions of the new rectangle.

Idon’t understand this.. will someone ? will mark brainliest along with 20 points.

Researchers were interested in whether relaxation training decreases the number of headaches a person experiences. they randomly assigned 20 participants to a control group or a relaxation training group and noted the change in number of headaches each group reported from the week before training to the week after training. which statistical analysis should be performed to answer the researchers' question?

Create a data set with 8 points in it that has a mean of approximately 10 and a standard deviation of approximately 1.