median = middle number
Total ten numbers so
median = (17 + b)/2
given median = 18
so
(17 + b)/ 2 = 18
17+b = 36
b = 36 - 17
b = 19
Now you have the data set
7, a , 12, 15 , 17, 19, 20, 22, 24 , 25
Mean = (7 + a + 12+ 15 +17 + 19 + 20 + 22 +24 +25)/ 10
Given mean = 17
so
17 = (7 + a + 12+ 15 +17 + 19 + 20 + 22 +24 +25)/ 10
17 = (a + 161) / 10
a + 161 = 170
a = 170 - 161
a = 9
answer
a = 9
b = 19
