At a party there are 30 students over the age of 18 and 20 students under 18. You
randomly choose 3 students over 18 and 2
students under 18 to interview. This is an
example of:
A. A convenience sample
B. A self-selected sample
C. A systematic sample
D. A random sample

D

Step-by-step explanation:

the answer is d. it needs to be a 20 character stament to answer

C

Step-by-step explanation:

4 puzzles in 3 hours

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