Statistics and Probability Answers

Present complete solutions for each item. Illustrate the normal curve if possible.

2. The scores of individual students on a national test have a normal distribution with mean of

18.6 and a standard deviation of 5.9. At Federico Ramos Rural High School, 76 students

took the test. If the scores at this school have the same distribution as national scores, solve

for the following:

a. determine the mean and standard deviation of the sampling distribution of the sample

mean.

b. find the probability that the sample mean falls between 17 and 20 (P(17 < x̅< 20).

c. the number of sample means that is above 19.3 kilograms.

How many possible samples n=2 can be drawn from a population of size 14?

Consider the population consisting of the values 1, 3 and 4. List all the possible samples of size 2 that can be drawn from the population with replacement. Then, compute the mean x— for each sample. Lastly, find the mean of the sampling distribution of means and the mean of the population.

the average grade of 30 students in their statistics and probability examination is 85 with a standard deviation of 5. find the interval for the true mean at 95% interval

12 entries in a painting competition were ranked by two judges , Judge I : 5, 2, 3, 4, 1, 6, 8, 7, 10, 9, 12, 11 and byJudge II: 4, 5, 2, 1, 6, 7, 10, 9, 11, 12, 3, 8. Calculate Spearman's rank correlation coefficient.

A manufacturer claims that only 4% of his products supplied by him are defective. A random sample of 600 products contains 36 defectives. Test the claim of the manufacturer.

Fit the parabola is Y=a X^2+bX+c for the data x: 1, 3, 4 , 6 ,8 ,9, 11, 14 and y: 1,2, 4, 4, 5, 7, 8, 9.

Pollsters are concerned about declining levels of cooperation among persons contacted in surveys. A pollster contacts 97 people in the 18-21 age bracket and finds that 82 of them respond and 15 refuse to respond. When 260 people in the 22-29 age bracket are contacted, 240 respond and 20 refuse to respond. Assume that 1 of the 357 people is randomly selected. Find the probability of getting someone in the 22-29 age bracket or someone who refused to respond.

Report the answer as a percent rounded to one decimal place accuracy. You need not enter the "%" symbol.

P(22-29 or refused) =

new york city typically has rain on about 16% of days in October what is the probability that it will rain on exactly 5 days in October and 15 days?

On a roulette wheel, the probability of "red" is 18/38, In 10 spins what is the probability of exactly 8 red outcomes?