Difference between revisions of "2016 AMC 12A Problems/Problem 4"
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<cmath>7x=540+x</cmath> | <cmath>7x=540+x</cmath> | ||
<cmath>6x=540</cmath> | <cmath>6x=540</cmath> | ||
| − | <cmath>x=\boxed{\textbf{(D)}\text{ 90}</cmath> | + | <cmath>x=\boxed{\textbf{(D)}\text{ 90}}</cmath> |
Revision as of 22:26, 3 February 2016
Solution
must be in the middle of the list. Order the known list first: 
.
occurs the most times, and it is the average of the list.
is either 
or 
because it is the median and the mode.
is the average of the set values.
![\[x=\frac{40+50+60+90+100+200+x}{7}\]](http://latex.artofproblemsolving.com/e/3/a/e3aaaa3c3d3bbc3b6c0e069af4175e70364be48a.png)
![\[x=\frac{540+x}{7}\]](http://latex.artofproblemsolving.com/6/f/e/6fea05ca3b0890dad230d1efe0e7fd712c6337fd.png)
![\[7x=540+x\]](http://latex.artofproblemsolving.com/2/5/0/25079bdfd04955e060ee8d0acc51fb4e891038b0.png)
![\[6x=540\]](http://latex.artofproblemsolving.com/6/b/7/6b7e58a412c03874549049365a1e237aeda0de52.png)
![\[x=\boxed{\textbf{(D)}\text{ 90}}\]](http://latex.artofproblemsolving.com/1/3/a/13a5a44206b6f69d0a76c2e47b9fa8fd78ce7398.png)
