Exam 1: Introduction to Statistics

Determine whether the given description corresponds to an observational study or an experiment. A doctor gives a new medication to half of his patients with the flu and a placebo To the other half of his patients with the flu.

Determine whether the given description corresponds to an experiment or an observational study. A stock analyst selects a stock from a group of twenty for investment by choosing the Stock with the greatest earnings per share reported for the last quarter.

There are many potential pitfalls that can cause problems when analyzing data. Which of these choices are not classified as a potential pitfall?

Identify the type of observational study used. A town obtains current employment data by polling 10,000 of its citizens this month.

A management survey for a company surveyed 235 employees. 44.7% of the employees surveyed were females. The number of males would be ___________________.

On a test, 74% of the questions are answered correctly. If 111 questions are correct, how many questions are on the test?

Subscribers of the women's magazine Cosmopolitan are asked to participate in a survey about preferred cereals for breakfast. Are the results likely to be representative of all women? Of all subscribers of Cosmopolitan? Why or why not?

Why do you think that cluster sampling is frequently used in practice?

Determine which of the four levels of measurement is most appropriate. Students' grades of A, B, or C, on a test.

Which of the following does not apply to the ratio level of measurement?

Given the data in the table, what issue can be addressed by conducting a statistical analysis of the values? Amounts of Saturated Fat (in grams) in Two-Once Regular and Low-Fat Muffins Regular 4.5 3.5 3.7 5.2 4.9 3.9 Low-Fat 1.2 2.1 2.2 1.8 1.6 2.2

Determine which level of measurement is appropriate. Salaries of college professors?

A marketing firm does a survey to find out how many people use a product. Of the one hundred people contacted, fifteen said they use the product. Identify the type of study used.

Why is cluster sampling frequently used in practice?

Would an observational study or an experiment be more appropriate to investigate the effects on humans of a substance known to be toxic? Explain.

Form a conclusion about statistical significance. Do not make any formal calculations. Either use the results provided or make subjective judgments about the results. Last year, the average math SAT score for students at one school was 475. The headmaster introduced new teaching methods hoping to improve scores. This year, the mean math SAT score for a sample of students was 481. Is there statistically significant evidence that the new teaching method is effective? If the teaching method had no effect, there would be roughly a 3 in 10 chance of seeing such an increase. Does the result have statistical significance? Why or why not? Does the result have practical significance?

Identify which type of sampling is used. The name of each contestant is written on a separate card, the cards are placed in a bag, and three names are picked from the bag.

Determine whether the given value is a statistic or a parameter. Thirty percent of all dog owners poop scoop after their dog.

Which of the following is an inappropriate way to deal with missing data?

A marijuana survey included 1610 responses from a list of approximately 241,500,000 adults in the U.S. from which every 150,000th name was surveyed. Identify which of these types of Sampling is used: