3. A sample of 25 hens from a normal population showed that the average egg laying is 250 eggs per year with a variance of 625 eggs. The company claimed that the average egg laying is 285 eggs per year. Test the claim of the company at 5% level of significance.

In general, how is the magnitude of the standard error of estimate related to the value of the correlation?

What proportion of the distribution of sample means is between a z  of 1.34 and z of -1.00?

This research was conducted with Korean adolescents in the Los Angeles area. Would you be willing to generalize the results of this study to Korean adolescents who live in other regions of the country? Why or why not.

The scores on a standardized test are normally distributed with a mean of 120 and standard deviation of 5. What test score is 1.1 standard deviations above the mean?

The results of a common standardized test used in psychology research is designed so that the population mean is 105 and the standard devlation is 30. A subject earns a score of 108. What is the Z-score for this raw score? Z-Score =

Professor Hayashi has implemented a new book for his Fall 2013 statistics course. He wants to see if the new book has an effect on the exam average for Exam 3. He knows that the Exam 3 mean for all students who have taken his statistic course over the past 10 years is 77.2. He collects some data from a sample of 9 students and finds that the Exam 3 mean for his Fall 2013 statistics students is 81.7 with a variance of 32.49.Measure effect size using percentage of variance

Two chemical companies can supply a raw material. The concentration of a particular element in this material is important. The mean concentration for both suppliers is the same, but you suspect that the variability in concentration may differ for the two companies. The standard deviation of concentration in a random sample of n₁ = 10 batches produced by company 1 is s₁ = 4.7 grams per liter, and for company 2, a random sample of n₂ = 16 batches yield s₂ = 5.8 grams per liter. Is there sufficient evidence to conclude that the two populations variances differ? Use a = 0.05. a. Because 0.321 < 0.657 <3.77, fail to reject the null hypothesis b. Because 0.265 < 0.657 <3.12, fail to reject the null hypothesis c. Because 0.386 < 0.657 <3.01, fail to reject the null hypothesis d. None among the choices

A researcher studying stress is interested in the blood pressure measurements of chief executive officers (CEOs) of major corporations. He has good reason to believe that the mean systolic blood pressure, μ, of CEOs of major corporations is different from 132 mm Hg, which is the value reported in a possibly outdated journal article. He plans to perform a statistical test. He measures the systolic blood pressures of a random sample of CEOs of major corporations and finds the mean of the sample to be 124 mm Hg and the standard deviation of the sample to be 20 mm Hg. Based on this information, complete the parts below.  Suppose the true mean systolic blood pressure of CEOs of major corporations is 132 mm Hg. Fill in the four blanks to describe a Type I error.         1. A Type I error would be (rejecting) or (failing to reject) the hypothesis       2. that μ is (less than) (less than or = to) (greater than) (greater than or = to) (not = to) or (= to)    3. the number (124) (132) or (20)…

Suppose the length of human pregnancies from conception to birth varies according to a distribution that is normal with mean of 266 days and standard deviation of “alpha”. 11.7% of pregnancies last 284 days or more, find the variance of the distribution .