Answer: Choice C
The mean will increase more than the median, but both will increase.
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Step-by-step explanation:
The original set is {1,2,3,4,5,6,7}
The mean is found by adding up the values and dividing by the number of values 7. The items add up to 1+2+3+4+5+6+7 = 28, so the mean is 28/7 = 4.
The median is the middle-most value. Cross off the first and last values to get the smaller subset {2,3,4,5,6}. Repeat again to get {3,4,5} and it should be clear that 4 is the median.
mean = 4
median = 4
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Now let's introduce the value "12"
The set is {1,2,3,4,5,6,7,12}
mean = (1+2+3+4+5+6+7+12)/8 = 40/8 = 5
median = 4.5 since it is halfway between the middle-most items 4 and 5
Both mean and median have increased. The mean has increased more.