Question 1087157: Please help me solve thise equation Make a list of four different number whose average works up to 25?
Found 2 solutions by jim_thompson5910, rothauserc:
Answer by jim_thompson5910(35256)   (Show Source):
You can put this solution on YOUR website! Here's one trick you can do. This isn't the only method as I'm sure there are others.
Start with a list of four copies of 25. So we have the list L1={25, 25, 25, 25}. Clearly the average is 25. We can add up the values to get 100 and then divide by 4 and sure enough the result is 25.
Now add 1 to any value you wish. Let's add 1 to the last copy to get this new list L2={25, 25, 25, 26}. If we compute the average of L2, then we get (25+25+25+26)/4 = 101/4 = 25.25 which is too high. We need to subtract 1 from some other element to counter balance things out. So let's subtract 1 from the first 25 to get the new list L3 = {24, 25, 25, 26} which computes the average (24+25+25+26)/4 = 100/4 = 25
Repeat the last two steps. Add 1 to the last value. Subtract 1 from the first value. We get this new list L4 = {23, 25, 25, 27}. The average is (23+25+25+27)/4 = 100/4 = 25.
Now apply these steps (of adding 1 and subtracting 1) to the inner values and we have L5 = {23, 24, 26, 27} getting the average to be (23+24+26+27)/4 = 100/4 = 25
As you can see there isn't a limit so you can keep going to manipulate values. Just make sure to counter balance any operation you do. If you add 1 to a certain element, then you must subtract 1 from another element, and vice versa.
Answer by rothauserc(4718)  (Show Source):
You can put this solution on YOUR website! (a + b + c + d) / 4 = 25
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a + b + c + d = 100
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any four numbers whose sum is 100 is a solution
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for example,
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10 + 30 + 40 + 20 = 100 and
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the average is 100/4 = 25
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