30,45,x,100; the mean is 60

if there are 4 numbers that average to 60, when mutiplied they must come up to: 60*4= 240

100+30+45= 175

240-175= 65

PROOF:

100+30+45+65= 240

240÷ 4

= 60

x=65

Step-by-step explanation:

Mean= sum of terms

number of terms

60=30+45+x+100

4

240=175+x

x=240-175

=65

where did you get them? if you picked from the grass, is is probably poisonous.

step-by-step explanation:

a 4/6 = 9/12   not proportional

step-by-step explanation:

to find which are not proportional, we can use cross products

if it is true, they are proportional.   if it is not true, they are not proportional.

a 4/6 = 9/12

4* 12 = 6*9

48 = 54

not this is not proportional  

b 2/3 = 12/18  

2* 18 = 3 * 12

36 = 36

this is proportional

c 5/4 = 10/8  

5*8 = 4*10

40 = 40

this is proportional

d 7/5 = 35/25

7*25 = 5 * 35

175 = 175

is proportional