Statistics and Probability Answers

A population consists of the numbers 2, 4, 8, 10 and 5. Let us list all 

the possible samples of size 3 from this population and construct the sampling 

distribution of the sample mean?

Assuming that the samples come from normal distribution, find the margin of error E given the following:

n = 10 and x̄ = 28 with s = 4.0, 90% confidence

A sample of 150 students were chosen at random from all grade 11 students in a private school in Pampanga. The sample indicated that 75% of them were in favor of having an educational trip. Find a) 95% and b) 99% confidence intervals for the proportion of all students who are in favor of having an educational trip. 

In a recent survey of 850 students, it was found that 476 of them have laptops. a. Find the sample proportion p ̂. b. Find a 95% confidence interval for the actual proportion of students who have laptops. 

Calculate the confidence interval to estimate the population proportion, given the following data: a. n=400; p ̂ = 0.70; confidence level : 95% and b. n=700; p ̂ = 0.45; confidence level : 99%. 

Out of the 150 randomly selected people in the mall, 45 of them were students. Compute the sample population. 

 In a random sample of 120 teachers, 48 of them have master’s degree. Find the value of p ̂. 

For a t-distribution with 14 degrees of freedom, find the value of t such that the area between –t and t is 0.90. 

Ali draws a ticket from box containing 2 bad, 10 good,and 5 very good tickets.Ahmed draws a next ticket from same box.What is probability of better performance of Ahmed than Ali?

A jar contains 8 green, 4 blue, 10 red, and 2 yellow Skittles. A Skittle is randomly drawn, replaced, then another is drawn. Find each probability.