the mean of a list of 80 numbers is 230. if the four number 145, 156, 210 and 255 are added what is the mean of the list of numbers

Question

johnweldon1993 · Answer

Well a mean, is a bunch of numbers (80 here) added up (to 230) and divided by the amount of numbers...again 80

So

Mean = 230 = x
                     ---
                       80

So to solve for 'x' you multiply both sides by 80...

230 x 80 = 18400

so

x = 18400

Now we add the remaining numbers you are given... +145 + 156 + 210 + 255 

This equals 19166

Now...we have 80 + 4 more entries...so that means 84...to find a new mean...we divide that 19166 by the 84...

which gives you...?