Statistics and Probability Answers

A food company is planning to market a new type of frozen yogurt. However, before marketing this
yogurt, the company wants to find what percentage of the people like it. The company’s management
has decided that it will market this yogurt only if at least 35% of the people like it. The company’s
research department selected a random sample of 400 persons and asked them to taste this yogurt. Of
these 400 persons, 112 said they like it. Test at 2.5% significance level, can you conclude that the
company should market this yogurt?

The manager of a restaurant in Malacca claims that waiters working in all restaurants in Malacca earn an average of RM150 or more in tips per week. A random sample of 25 waiters selected from restaurants of Malacca yielded a mean of RM139 in tips per week with a standard deviation of RM28. Assume that the weekly tips for all waiters in Malacca have a normal distribution. Using 1% significance level, can you conclude that the manager’s claim is true?

a teacher is going to choose a pupil at random from each of these classes. In which class is she more likely to choose a boy? in class 9a there are 13 boys and 15 girls however in class 9b there are 12 boys and 14 girls. you must show your working.

the values below are the scores (maximum 20) obtained in an aptitude test by a random sample of 11 graduates. it is known that for the non-graduate population the median score is 12. is there evidence, at the 10% significance level, that graduates achieve a higher median score than the non-graduate population?
14 15 09 10 10 13 14 19 12 16 13

A recent survey of 200 households showed that 8 had a single male as the head of the household. For years ago, a survey of 200 households showed that 6 single male as the head of the household. Alpha = 0.05, can it be concluded that the proportion has changed.

Prof. Coffey is studying a population of the elementary school pupils in a school district with data on all its children. Dr. Meyer suggests she calculate a confidence interval to estimate the mean age of these children. Prof. Coffey responds that it is not necessary. Explain why Prof. Coffey is correct.

The diameter of a ball bearings produced by a machine is random variable having a normal distribution with mean 6.00 mm and standard deviation 0.025 mm. If the diameter tolerance ±1%, find the proportion of ball bearings produced that are out of tolerance.

Identify the null hypothesis Ho and the alternative hypothesis H1. The manufacturer of a refrigerator system for beer kegs produces refrigerators that are supposed to maintain a true mean temperature, µ, of 46 degree F, ideal for a certain type of German pilsner. The owner of the brewery does not agree with the refrigerator manufacturer, and claims he can prove that the true mean temperature is incorrect.

A hospital claims that the proportion of full-term babies born in the hospital who weigh less than seven pounds is no more than . Suppose that we want to carry out a hypothesis test for this claim, suspecting otherwise. State the null hypothesis and the alternative hypothesis that we would use for this test.

Ho
H1

) If X is a Poisson variate and p(X = 3) > p(X = 2) then find the minimum value of mean