Question 1153914
<br>
{{{(2(1)+4(2)+6(3)+9(4)+x(5)+9(6)+4(7))/(2+4+6+9+x+9+4) = 5.5}}}<br>
{{{(146+5x)/(34+x) = 5.5}}}<br>
{{{146+5x = 187+5.5x}}}<br>
{{{-41 = .5x}}}<br>
{{{x = -82}}}<br>
Obviously the data is bad....<br>
Looking at the data for marks 1-4 and 6-7, the mean is<br>
{{{(2(1)+4(2)+6(3)+9(4)+9(6)+4(7))/(2+4+6+9+9+4) = 146/34}}} = 4.29 approximately.<br>
You can't add marks of 5 to a mean of 4.29 and end up with a mean of 5.5.<br>