Mathematics, 08.10.2020 01:01 kcnawlay170
oes regular exercise reduce the risk of a heart attack? Provided are two ways to study this question. A researcher finds 20002000 men older than age 4040 who exercise regularly and have not had heart attacks. She matches each with a similar man who does not exercise regularly, and she follows both groups for 55 years. Another researcher finds 40004000 men older than age 4040 who have not had heart attacks and are willing to participate in a study. She assigns 20002000 of the men to a regular program of supervised exercise. The other 20002000 continue their usual habits. The researcher follows both groups for 55 years. Select the correct explanation clearly detailing why the second design will produce more trustworthy data.
Answers: 1
Mathematics, 21.06.2019 14:00, Dweath50
(a) calculate the molarity of a solution that contains 0.0345 mol nh4cl in 400 ml of solution. (b) how many moles of hno3 are present in 35.0 ml of a 2.20 m solution of nitric acid? (c) how many milliliters of 1.50 m koh solution are needed to supply 0.125 mil of koh ?
Answers: 2
Mathematics, 21.06.2019 18:00, brooke0713
Galen sold tickets of his church’s carnival for a total of $2,820. children’s tickets cost $3 each and adult tickets cost $5 each. the number of children’s tickets sold was 30 more than 3 times the number of adult tickets slod. how many children’s ticket and how many adult tickets did he sell?
Answers: 2
Mathematics, 21.06.2019 19:30, pillgiing
Acar started driving from city a to city b, distance between which is 620 miles, at a rate of 60 mph. two hours later a truck left city b and started moving towards city a at a rate of 40 mph. what distance from city a is the point where the truck and the car will meet?
Answers: 1
oes regular exercise reduce the risk of a heart attack? Provided are two ways to study this question...
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