1) A. Biased because the population could be uneven. Too many of one ethnicity, too many of one gender, etc.
2) I believe this one is C. because there are not enough people. You need to survey the majority of parents instead of a selected few.
3) There are 80 green marbles per 500, therefore calculate the percentage.

or

percent. Multiply

percent or

times 25. It gives you

.
4) This one is a probability thing too. For every 500 batteries, there are 3 that are defective, therefore,

.

5) Yet another one. Add up all the nuts and you get

. The chance of getting a cashew from these

is:

.
Therefore:
C^2+7 would equal 88. the first equation states that C=9, so you can just plug in 9 for C
Answer:
15.75
Step-by-step explanation:
30% of 350=105 15% of 105=15.75
130.95 rounded to the nearest tenths place is 131.0
A five or above means you round up.