1) the mean of eight numbers is 75. if the mean of three of the numbers is 60, find the mean of the remaining five numbers

2) the mean of set of ninety numbers is 47. one third of the numbers are increased by six. what is the mean of the new set?

3) a fiity- foot watering hose has a 1 inch inside diameter. to the nearest hundredth how many cubic inches of water can the hose hold? use 3.14 for pi

1.
mean=average of all them

(a+b+c+d+e+f+g+h)/8=75
a+b+c+d+e+f+g+h=600

(a+b+c)/3=60
a+b+c=180
subsitute

a+b+c+d+e+f+g+h=600
180+d+e+f+g+h=600
minus 180 both sides
d+e+f+g+h=420
divvide both side by 5
(d+e+f+g+h)/5=84
the mean is 84

2.
1/3 are increased by 6
that means 30 of them are increased by 6
30*6=180
adds 180 to total
180/90=2
increases mean by 2
47+2=49
new mean is 49

c.
v=hpir^2
h=50ft, or 12*50in or 600in
r=1
v=600pi1^2
v=600pi
use 3.14
v=1884 cubic inches

2160ft^3 i think you could use a formala to you out with this in the future