Answer:
a) 0.0016
b) 0.0224
Step-by-step explanation:
If every question has 5 possible answers, the probability of getting the correct answer by guessing would be 0.20. The probability of getting an incorrect answer would be 0.80.
a)Find the probability she lucks out and answers all four questions correctly.
To do this, Allison would have to guess right the first, second, third AND fourth answers. Therefore, we have to multiply the probabilities:
0.20 x 0.20 x 0.20 x 0.20 = 0.0016
The probability that she answers all 4 questions correctly is 0.0016.
b) Find the probability that she passes the quiz.
To pass the quiz, she has to have three OR 4 correct answers:
- The probability that she has 3 correct answers is: 0.20 x 0.20 x 0.20 x 0.80 (since she has to have 1 correct answer and 1 incorrect one) = .0064.
- We already calculated the probability that she guesses 4 answers correctly: 0.0016.
Now, we have to sum up these two scenarios:
0.0064 + 0.016 = 0.0224.
Thus, the probability that she passes the quiz is 0.0224
Answer: Given a sample of 200, we are 90% confident that the true proportion of people who watched educational TV is between 72.1% and 81.9%.
Step-by-step explanation:
![\frac{154}{200} =0.77](https://tex.z-dn.net/?f=%5Cfrac%7B154%7D%7B200%7D%20%3D0.77)
![1-0.77=0.23](https://tex.z-dn.net/?f=1-0.77%3D0.23)
=0.049
0.77±0.049< 0.819, 0.721
An input-output table, like the one shown below, can be used to represent a function. Each pair of numbers in the table is related by the same function rule. That rule is multiply each input number
Answer: the percent of the students at this university are foreign = 30%
Step-by-step explanation:
Given: Probability that college students are foreign students who also smoke: P(S|F)=0.12
Probability that foreign college students smoke P(S∩F)=0.4
The probability that the students at this university are foreign :
[By conditional probability formula]
![=\dfrac{0.12}{0.4}\\\\=0.3](https://tex.z-dn.net/?f=%3D%5Cdfrac%7B0.12%7D%7B0.4%7D%5C%5C%5C%5C%3D0.3)
Hence, the percent of the students at this university are foreign = 30%
Answer: C. Infinitely many
Step-by-step explanation:
You can replace z with any number, and there are an infinite amount of numbers.