Stats Help for College-level Students

ANOVA

Response variable: personal ratings (how a subject likes or dislikes a particular concentration of a solution on a scale from 1 to 10). Independent variable 1: concentrations of a solution (5 levels: 5%,10%, 20%, 40%, 80%). Independent variable 2: two groups of subjects: Group A (sample size 50), Group B(sample size 60). ...continues

The mean of the exponential distribution.

Prove that the mean of the exponential distribution with parameter a is 1/a .

Working with binomial probability.

If the parents have 5 children, the number who have type O blood is a random variable X that has the binomial distribution with n=5 and p=0.25 a) What are the possible values of X? b) Find the probability of each value of X. Draw a histogram to display this distribution. (Because probabilities are long-run proportions, a hi ...continues

Multiplication Rule for Independent Event/General Addition rule for any two events

The distribution of blood types among white type Americans is approximately as follows: 37% type A, 13% type B, 44% type O, and 6% type AB. Suppose that the blood types of married couples are independant and that both the husband and the wife follow this distribution. a)An individual with type B blood can safely receive transfu ...continues

Binomial Probability

A factory employs several thousand workers, of whom 30% are Hispanic. If the 15 members of the union executive committee were chosen from the workers at random, the number of Hispanics on the committee would have the binomial distribution with n=15 and p=0.3 a)What is the probability that exactly 3 members of the committee are ...continues

Normal Approximation

Here is a simple probability model for multiple-choice tests. Suppose that each student has probability p of correctly answering a question chosen at random from a universe of possible questions. (A strong student has a higher p than a weak student.) Answers to different questions are independant. Jodi is a good student for whom ...continues

Hypothesis testing: Two tailed test for difference between proportions, t test for dependent samples political poll,

1. A political poll immediately prior to a state election reveals that 145 out of 250male voters and 105 out of 200 female voters intend to vote for the Independent candidate. Can we infer at the 5% significance level that the proportions of male and female voters who intend to vote for the Independent candidate differ? ...continues

Hypothesis testing: ANOVA, Kruskal Wallis test

1 There are four McDonalds restaurants in a particular area. The numbers of burgers sold at the respective restaurants for each of the last 4 days are shown below. Restaurant 1 2 3 4 Day 1 81 79 55 36 2 83 69 65 45 3 67 59 58 62 4 77 69 73 58 ...continues

Statistics

Life insurance companies are keenly interested in predicting how long their customers will live.......

regression analysis

The British Bankers Association wanted to look at the relationship between the amount of deposits made in billions and the number of customers the bank had............