<p>A data set has 15 elements. The 15 elements in a second data set are obtained by multiplying each element in the first data set by 10. The 15 elements in a third data set are obtained by decreasing each element of the second data set by 20. The median of the third data set is 50. What is the median of the first data set?</p>
<p>How could I show the answer is 7? What do I let “x” be for this problem??</p>
<p>X - 10x - 10x-20</p>
<p>10x-20=50
10x=70
x=7</p>
<p>I’m not sure what “x” represents though–is it the sum of the elements or…?? Also, how do you obtain the last data set of 10x - 20 (wouldn’t it be 300 instead of 20 since we have to subtract 20 from each element?) and why do you set it equal to 50? I need a little more explanation :(</p>
<p>X is the median of the first data set.</p>
<p>The median is only one number</p>
<p>Take this data set: 4, 7, 8, 9, 11</p>
<p>The median is 8, since its the “middle”.</p>
<p>You can call it X since you don’t know it</p>