Exam 1: Introduction to Statistics

Explain the difference between stratified and cluster sampling?

The four levels of measurement that are commonly used for classifying data are ratio, ________, ________, and ________.

Identify which type of sampling is used. A research team wants to study the demographics of college students in the U.S. using proportionate samples of students in majors reflecting actual U.S. percentages.

A gardener has 75 clients, 45% of whom are businesses. Find the number of business clients.

Would an observational study or an experiment be more appropriate to investigate the effects on fertilizer on plant growth? Explain.

The similarity between an ordinal level of measurement and an interval level of measurement is that _______________.

Correlation does not imply _____________.

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

Explain what is meant by the term "confounding," and give an example of an experiment in which confounding is likely to be a problem.

A tax auditor selects every 1000th income tax return that is received. Identify which of these types of sampling is used.

Determine whether the given value is a discrete or continuous variable. People are asked to state how many times in the last month they visited their family doctor.

Determine whether the given value is from a discrete or continuous data set. The time it takes a computer to complete a task.

Use critical thinking to develop an alternative conclusion. A study shows that the number of reported sexually transmitted diseases was significantly higher for high schools that offered courses in sex education than for high schools that did not. Conclusion: The introduction of sex education courses at the high school level has resulted in increased promiscuity among teens.

A ______________ is the complete collection of all measurements or data collected, whereas, a _____________ is a subcollection of members selected from the complete collection.

Distinguish between categorical and quantitative data. Give an example of each?

An education expert is researching teaching methods and wishes to interview teachers from a particular school district. She randomly selects ten schools from the district and interviews All of the teachers at the selected schools. Does this sampling plan result in a random sample? Simple random sample? Explain.

Identify which type of sampling is used. A tax auditor selects every 1000th income tax return that is received.

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

Identify the sample and population. Also, determine whether the sample is likely to be representative of the population. An employee at the local ice cream parlor asks three customers if they like chocolate ice cream.

The table shows the weights (in pounds)and monthly incomes (in dollars)of nine randomly selected women between the ages of 18 and 65. Weight (lb) 113 132 155 122 166 140 118 129 185 Monthly Income (dollars) 1420 3650 5475 2310 4710 2910 1720 2460 4115 If we use statistical methods to conclude that there is a correlation (or relationship or association)between the weights of women and their monthly incomes, can we conclude that by increasing her weight a woman can increase her monthly income?