Exam 21: Introduction to Statistical Analysis

One hundred students took an examination; the mean of the test was 45%, and the median 38%; 70 students scored below the mean, but 3 scored more than 96%. This would represent what type of distribution?

If a researcher wishes to predict with 97.5% accuracy, the level of significance would be:

Which of the illustrations of distribution curves demonstrates the least amount of variation in the scores?

Which of the following are true about Type II error?

Which of the following should a reader of a research article be able to do, in order to decide whether the article's statistics are correctly selected and applied?

There are four data sets: A: 1, 1, 1, 1, 1, 10, 10, 10, 10 B: 2, 2, 2, 2, 4, 8, 8, 8, 9 C: 3, 4, 4, 5, 5, 5, 6, 6, 7 D: 1, 2, 3, 4, 5, 6, 7, 8, 9 What is the mode of the four individual data sets?

Which group of numbers is the best example of a normally distributed data set?

What is the symbol for?

A researcher states in an article that a new experimental treatment, trialed in the outpatient setting in a tri-physician practice in northern Oregon, produces better outcomes than the control treatment for patients with COPD. The p-value given is p < 0.05. What does this mean?

A null hypothesis is stated. The null hypothesis is, "There is no difference between one baby aspirin every day and no baby aspirin at all in prevention of myocardial infarction." What are the implications of this statement, concerning the null hypothesis and Type II error?

A researcher is attempting to decide whether to hire a statistician to assist with the statistical aspects of the study. If the researcher cannot perform all of the following for a quantitative study, why should a statistician be contacted?