One homework problem I have asks me to find what age added to a set of 15 ages, would lead to a mean of 54.94. The total of the 15 ages given minus the missing age = 828.
I am not sure if I did this right, but I set up the following equation to locate the X variable (the missing age in the line of ages).
828+x divided by 16 = 54.94 or (828 + X)/16 = 54.94
I seem to forget how to isolate the X variable. No matter what I do, it doesn't seem to work out. Perhaps I didn't even set it up correctly.
I would appreciate any help on this.
Thank you. I appreciate you help. As a follow up, so I know for the future, why is it that we used dual variables instead of simply plugging in the sum of the original figures? What principle?
And thanks again. I will make up another problem for myself and reverse engineer your answer.
I'm looking at this again and wondering if I took the above sentence correctly. Literally speaking your statement implies that (sum of 15 ages) - (missing age) = 828, which is why my solution involved two variables because we don't know what the sum of the 15 ages is.
However from your followup post and re-reading the question I am wondering if this was a typo. In your original post were you trying to say that the sum of the 15 ages is 828? If so then the equation you posted is correct:
<-- Multiply by 16
-Dan