mean is add the numbers and divide the result by how many numbers there are
mean=23
1 missing number which is x
5 numbers including missing one
(15+17+28+30+x)/5=23
solve for x
multiply both sides by 5
15+17+28+30+x=115
add like terms
90+x=115
subtract 90
x=25
the missing number is 25
Answer:
Mean is the average of the sum of all 5 numbers.Therefore 23x5 = 115
Step-by-step explanation:
Therefore 23x5 =115
lets call the missing number X
15 +17+x+28+30=115
x+90=115
x=115-90
x=25