Hello, I would appreciate any help with the following problems:
The discrete random variable X is the number of students that show up for Professor Smith's office hours on Monday afternoons. The table below shows the probability distribution for X. What is the probability that the total number of students showing up on Monday afternoons in 2 weeks (assuming independence of results in the two Mondays) is less than 3?
I had a similar problem like this one but it did not ask for two weeks of probability and it said "at least 1". I have no idea what to do for this one because they threw that "2 weeks" in there. What I initially tried to do was: (0)(.45)+(1)(.35)+(2)(.15) / (.45+.35+.15) and this gives me 68.42. The answer, however, is 0.775. As I said, I am completely lost and have no idea how to get 0.775.
My second question is this:
What percent of cases are likely to be between 86 and 93 in a normal distribution with mean 87 and variance 4?
What I did was 86-87/4 and I got 0.0987. Then I did 93-87/4 and I got 0.4332. Added those together I get 0.5319 but apparently the answer is .6902.
Any help appreciated please. Thank you,
Laythen
The discrete random variable X is the number of students that show up for Professor Smith's office hours on Monday afternoons. The table below shows the probability distribution for X. What is the probability that the total number of students showing up on Monday afternoons in 2 weeks (assuming independence of results in the two Mondays) is less than 3?
X | 0 | 1 | 2 | 3 |
P(X) | .45 | .35 | .15 | .05 |
I had a similar problem like this one but it did not ask for two weeks of probability and it said "at least 1". I have no idea what to do for this one because they threw that "2 weeks" in there. What I initially tried to do was: (0)(.45)+(1)(.35)+(2)(.15) / (.45+.35+.15) and this gives me 68.42. The answer, however, is 0.775. As I said, I am completely lost and have no idea how to get 0.775.
My second question is this:
What percent of cases are likely to be between 86 and 93 in a normal distribution with mean 87 and variance 4?
What I did was 86-87/4 and I got 0.0987. Then I did 93-87/4 and I got 0.4332. Added those together I get 0.5319 but apparently the answer is .6902.
Any help appreciated please. Thank you,
Laythen