Answer:
8. 15
10. 90
12. 36
Step-by-step explanation:
8.
The mean of the 5 data is 51.
(55 + 60 + 35 + 90 + x) ÷5 = 51
(240 + x) ÷5 = 51
240 + x = 255
x = 15
10.
The mean of the 5 data is 127.
(100 + 112 + 98 + 235 + x) ÷5 = 127
(545 + x) ÷5 = 127
545 + x = 635
x = 90
12.
The mean of the 5 data is 40.
(34 + 56 + 45 + 29 + x) ÷5 = 40
(164 + x) ÷5 = 40
164 + x = 200
x = 36
