Answer:
One set of prices could be: {275,300,450,600,675}
Another set could be: {275,300,450,600,675}
There are many other solutions possible.
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Explanation:
A = {450, 275, 675, 490, 300}
B = {275, 300, 450, 490, 675}
Set A is the original set of values in the order they were given to you. Set B is the sorted version of set A from smallest to largest.
The mean is found by adding up the values and dividing by 5 (because there are five items in the set).
The mean is (275+300+450+490+675)/5 = 2190/5 = 438. The shopkeeper wants to increase the mean to something larger, but keep the median and range the same.
The median is the middle most number. In set B, we can see that is 450. So the median is 450. We want to keep the median the same at 450.
The range is the difference in min and max
range = max - min = 675-275 = 400
We want to keep the range at 400
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There are a number of ways to increase the mean, while keeping the median and range the same.
Let's say we keep the min and max the same. In order to increase the mean, we need to increase the 490 (second largest value) to something larger. Let's bump that up to 600 for instance.
Recomputing the mean gets us
(275+300+450+600+675)/5 = 2300/5 = 460
The old mean was 438 and the new mean is now 460. The mean has increased. This is due to the larger price pulling on the mean to get the mean to increase.
The median is still 450 because it's still in the direct middle of set C
C = {275,300,450,600,675}
The range is still the same as well because we haven't changed the min and max.
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So one possible set could be
C = {275,300,450,600,675}
We could also have
D = {275,400,450,500,675}
The difference is that the 300 bumped to 400, and the 600 dropped to 500. You should find that the median and range are the same, while the mean is 460.
There are many possible solutions here.
