Answer: Choice C
They should be blocked by pain resistance so the subjects are as similar as possible.
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Explanation:
The process of blocking in statistics is where we group up people in blocks, and each block is determined by a characteristic of some sort. In this case, we're grouping people up by pain resistance level. Those very resistant to pain will be in one group, while those who easily feel pain will be in another block, and so on. It might be effective to have a pain scale and sort people by that.
Blocking is done so that we eliminate unwanted variability. We are testing the effectiveness of the itching cream, so all we care about is if the itch reduces or not. We aren't worried about the levels of pain. However, it says that "Previous studies have shown the effects of treatment may vary based on a subject's pain resistance". So we group up the people by pain tolerance to help eliminate the variability of pain tolerance levels.
This is why choice C is the final answer.
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Extra info:
- Choice A is false because a person's name doesn't have anything to do with if the treatment works or not.
- Choice B is false because we weren't given any info to indicate it being true. It may be true, but we simply don't have enough info to confirm it.
- Choice C is false for similar reasons as choice B.
The local gym holds three 45-minute workout sessions and two 30-minute sessions each week. Then the, total number of minutes Judy worked out for the week was 155 minutes.
We are to determine the total number of minutes Judy worked out for the week.
The gym holds three 45-minute workout sessions and two 30-minute sessions each week
So,
We can write,
The total number of minutes the gym holds workout sessions is
3 × 45 + 2 × 30
= 135 + 60
= 195 minutes
Also, from the information,
Judy left 5 minutes early during the 30-minute sessions and 10 minutes early during the 45-minute sessions.
The total number of minutes Judy didn't attend is
= 3 × 10 + 2 × 5
= 30 + 10
= 40 minutes
Then,
The total number of minutes Judy worked out for the week was,
= 195 minutes - 40 minutes
= 155 minutes
Therefore,
The total number of minutes Judy worked out for the week was 155 minutes.
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Answer:
Step-by-step explanation:
For mixture problems, it is convenient to define a variable to represent the amount of the greatest contributor. Let x represent the amount of 22% solution in the mix. Then 4.8-x is the amount of 10% solution.
The amount of alcohol in the mix is ...
0.22x +0.10(4.8-x) = 0.12(4.8)
Eliminating parentheses, we have ...
0.22x -0.10x +0.10(4.8) = 0.12(4.8)
Subtracting (0.10)(4.8) and combining x-terms gives ...
0.12x = 0.02(4.8)
x = (0.02/0.12)(4.8) = 0.8 . . . . . divide by the x-coefficient
The scientist needs 0.8 L of 22% solution and 4.0 L of 10% solution.
The answer for this question is Option B : 12.28
