Statistics and Probability Answers

A computer is programmed to randomly present stimuli that vary in shape (square and circle). The program is written such that a square is 5 times more likely to appear than a circle. What is the probability that the first figure presented on the screen will be a circle? What is the probability that the first figure presented on the screen will be a square?

A hundred squash balls are tested by dropping from a height of 100 inches and measuring the height of the bounce. A ball is “fast” if it rises above 32 inches. The average height of bounce was 30 inches and the standard deviation was ¾ inches. What is the chance of getting a “fast” standard ball?

A school cafeteria offers a choice of turkey,ham, or tuna for a sandwich. With each sandwich you have a choice of milk or lemonade as a drink. What are all the possible combinations of sandwiches and drinks? What is the probability of picking a turkey sandwich with lemonade? What is the probability of picking milk as a drink with any sandwich?

14. a national retail foundation found households intended to spend an average of $649 during the december holiday season(The wall street journal, december 2nd 2002). Assume that 600 households were sampled and the sample standard deviation was $175.

A. what is the point estimate of the population mean?

B.What is the standard error of the sample mean?

C. what is the critical value used for a 95% confidence level?

D. construct a 95% confidence interval for the population mean of household spending.

E.Write a sentence about the confidence interval and explain what the interval tells you.

15.The national mean sales price for new one-family homes is $181,900(the new york times almanac 2000) A sample of 40- one family home sales in the South showed a sample mean of $166400 and a sample stardard deviation of 33,500.

A. formulate the null and alternative hypothesis that can be used to determine whether the sample data support the conclusion that the population mean sales price for new one family homes in the south is less than the national mean of 181,900.

B. compute the test statistic for the hypotheses.

C.find a critical value for this test. Using alpha=.05 what is your conclusion about the hypotheses.

D.state your conclusion within the context of the problem.

A salesman is known to sell a product in 3 out of 5 attempts. while another salesman in 2 out of 5 attempts. Find the probability that
1.no sale while happen
2. either of them will succeed in selling the product

Is this a one- or two tailed test? An LU professor is interested in whether there is a difference between undergraduate students and graduate students in the amount of time spent praying each day. The professor gathers information from random samples of undergraduate and graduate students on the LU campus. The amount of time praying is normally distributed and is measured on an interval/ratio scale.

the probability that a man will be alive in 25 years is 3/5 and probability for his wife in 25 year is 2/3. find probability that a) both will be alive in 25 years b) only the wife will be alive in 25 years solution

A and B are two students .Their chances of solving a problem correctly are 1/3 and 1/4.If the probability of their making a common error is 1/20 and they obtain the same answer then the probability of their answer to be correct is?

A.1/12 B.1/40 C.13/120 D.10/13

The events X and Y are independent. Calculate the P(X and Y) if P(X) = 0.64 and P(Y)=0.23. Hence find P(X or Y)

An ordinary die is thrown. Find the probability that the number obtained is a multiple of 2 and the probability that it is less than 4