Answer:
1 - a/variable
2 - d/statistic
3 - b/population
4 - c/data
5 - e/parameter
6 - f/sample
I did comment asking if the two you'd already selected were definitely correct, but no answer was given, so I apologise if this is wrong. This is what I would put.
Answer:

Step-by-step explanation:
First, use distribution to simplify

Then, simplify further by combining like terms

Solve

Answer: a) 0.2222, b) 0.3292, c) 0.1111
Step-by-step explanation:
Since we have given that
Let the probability of getting head be p.
Since, its head is twice as likely to occur as its tail.

a)If the coin is flipped 3 times, what is the probability of getting exactly 1 head?
So, here, n = 3


Now,

b)If the coin is flipped 5 times, what is the probability of getting exactly 2 tails?
2 tails means 3 heads.
So, it becomes,

c)If the coin is flipped 4 times, what is the probability of getting at least 3 tails?

Hence, a) 0.2222, b) 0.3292, c) 0.1111