1. ## Competition results

Competition results:

Result 10 20 30 40 50
Participants 1 2 5 k 3

Mean value of the results is 34. $k=?$

Help?

2. If the mean value of the results is 34, then you need to solve the following for $k$:

$\frac{1(10)+2(20)+5(30)+k(40)+3(50)}{1+2+5+k+3}=34$

3. The mean is equal to the sum of the results divided by the sum of the competitors, so:

$\frac{10+20+30+40+50}{1+2+5+k+3}=34$

From there, it's simple algebra. Solve for k.

4. Originally Posted by downthesun01
The mean is equal to the sum of the results divided by the sum of the competitors, so:

$\frac{10+20+30+40+50}{1+2+5+k+3}=34$

From there, it's simple algebra. Solve for k.
cpbrunner's got it right. You have to take the frquencies into account on the numerator. downthesun01 hasn't.

5. My mistake. You're totally right