The value of a would be 4.2, because the negatives cancel out each other.
Answer:
B: The mean study time of students in Class B is less than students in Class A.
Step-by-step explanation:
To find out why answer B is the right answer, I will give you facts from each option.
Option A is false. <em>The mean study time in Class A is 4.8. Meanwhile in Class B it is 4. For Class A, sum up the 20 study times which is 96 and divide them by 20, you will get 4.8 hours of mean study time. For Class B, the sum of the 20 study times is 80, which divided by 20 will be 4.
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Option B is True. <em>See previous explanation.
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Option C is False. <em>The median study time in Class B is 4. The median study time in Class A is 4.8,
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Option D is False. <em>The range in Class A is from 2 to 8. The range in Class B is from 2 to 7.
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Option E is False: <em>The mean and median study time of these classes is different.</em>
You can solve this one by adding their rates, but you have to invert the numbers they give you to find the rate. Rate is measured in something per unit of time, and "per" indicates division. So the rates are: 1/3 of an hour (Sally) and 1/6 of an hour (Steve). So add the rates: 1/3 + 1/6 = 1/2. (1/3 is 2/6, and 2/6 + 1/6 = 3/6). Since their combined rate is 1/2 of a room in one hour, it takes them two hours to paint the room.
This answer makes sense: It takes Sally three hours by herself; with Steve's help, she's faster, but not THAT much faster, because he's pretty slow. You can often spot-check word problem answers like this by giving it a common sense once-over. If we came up with four hours, that would clearly be wrong: it should take her LONGER if she's getting help.
Answer:
0.28
Step-by-step explanation:
28 divided by 3 is 9.33333333
3 divided by 28 is 0.10714286
