# probability estimate

1. ### Representative sample - how to decide

I am interested in understanding some of the Covid 19 statistics being thrown around. What I want to know is how to figure out whether a sample that was used to generate probabilities was actually representative of the population that was supposed to be sampled. I want to do this 'backwards' so...
2. ### Statistical significance/ probability

I have data for number of different vehicle types (cars, 2-Wheelers, 3-Ws, other) and which vehicle is following (going behind) which vehicle in 5 lanes (one direction). For example, In this table, 3Ws are following 120 2Ws and 90 cars. In other table it shows total number of vehicles present...
3. ### Exercise on standard distribution

Hello, Suppose I want to calculate the probability for a user to pass from a basic to a premium account within the end of Q1 (i.e. end of march). I know that this is distributed with mean=50 days and st.dev=10 days, then the probability that a user pass to a premium account within the end of...
4. ### What will be the Probability?

If a treatment for cancer has 90% success rate, the remaining 10% die. If two patients come for treatment, what is the probability that one will die?
5. ### comparing groups and the significance of two outcomes in each group

Hi, It's been 10 years since I picked up a stats book and wondering what's the best tool for the job. Given 2 systems, 3 categories in each system (better, same, worse) and for each category two outcomes (a win or loss). Is there a statistical significance of a win or loss between the 3...
6. ### Using probit model

Could anybody explain to me how to work with a model based on probit analysis? I have for example a model like this: Z=-2,067-2,324x+3,213y+1,782v (x, y, v will be replaced by measured values) and I would like to get a probability. I know I have to use several steps but i have no idea which...
7. ### Selection probability + time variable?

Greetings statisticians, I seek advice regarding a probability of selection. Here is the scenario: I, living in the US, have a music collection totaling 1000 CDs. A friend, living in Southeast Asia, has a collection totaling 2000 CDs. Given that we have similar musical interests yet live in...
8. ### Classical Probability

Greetings from new comer! Here is my question I could not figure it out by myself: There are two types of bags H and R in a single box (black box and you can't see through!). The number of the two types of bags are more than 10,000 that can be treated as infinite. In bag type H there are red...