1. To find the probability that a household chosen at random does not have two sets, we need to find the complement of the probability that a household chosen at random does have two sets.
So, we can calculate the probability that a household chosen at random does have two sets as 39%.
The probability that a household chosen at random does not have two sets is equal to 1 - 0.39 = 0.61.
Therefore, the answer is C) 0.61.
2. The probability that a randomly selected U.S. adult stated that their main source of news was not the internet can be found by subtracting the probability that their main source of news was the internet from 1.
The number of U.S. adults who stated that their main source of news was the internet is 681 out of 920.
So, the probability that their main source of news was not the internet is (920 - 681) / 920 = 239 / 920 ≈ 0.2598.
Therefore, the answer is D) 0.26.
3. The probability of guessing one question correctly is 1/4, and the probability of guessing one question wrong is 3/4.
To find the probability of getting at least one question wrong if you just guess, we can find the complement of getting all questions right.
The probability of getting all questions right is (1/4) * (1/4) * (1/4) * (1/4) * (1/4) = 1/1024.
So, the probability of getting at least one question wrong is equal to 1 - 1/1024 = 1023/1024 ≈ 0.99902.
Therefore, the answer is B) 0.99902.
4. The probability of making a free throw is 99% or 0.99.
Since the free throw shots are independent of each other, the probability of making three consecutive free throws is (0.99) * (0.99) * (0.99) = 0.9703.
Therefore, the answer is C) 0.9703.
5. To find the probability of a grade less than a C, we need to add up the probabilities of getting grades of D and F.
The probability of making a D is 20%, and the probability of making an F can be calculated by subtracting the probabilities of making A, B, C, and D from 1: 1 - (0.15 + 0.20 + 0.25 + 0.20) = 1 - 0.80 = 0.20.
Therefore, the probability of a grade less than a C is 0.20 + 0.20 = 0.40.
Therefore, the answer is E) 40%.