Exam 4: Central Tendency and Dispersion

If everyone in a class of 35 students got an exam score of 75, the value of the variance would be

The registrar has nominal-level data on students' racial classification. What would be an appropriate measure of central tendency to report?

A standard deviation is

To locate the range in which the middle 80% of the class scored on an exam, you would want to see which percentiles?

You want to see the mode and percent distribution for a variable. Name one SPSS procedure that would give you this.

Exactly half the class got a 70 on an exam and exactly half got a 90 on the exam. The median is

What is the lowest level of measurement for which it is permissible to calculate a mean?

Answer the questions that follow this SPSS output:   ABORTOK is an interval/ratio variable that measures a person's willingness to allow abortion to be legal. High scores indicate greater willingness; low scores indicate less willingness. The following figure describes the scores on ABORTOK for the baby boom twentysomethings and for the genXY twentysomethings. A) In which group was there more disagreement on the subject of abortion: the baby boom twentysomethings, the genXY twentysomethings, or was the amount of disagreement within the two groups exactly the same? ____________________ B) Justify your answer in no more than two sentences. Name the statistic(s) that backs up your conclusion and indicate its value(s).

What is the lowest level of measurement for which it is permissible to calculate a minimum?

If the standard deviation in commuting time to work is 9 minutes, the variance is

What univariate statistics are usually used to describe the distribution of cases on an interval/ratio variable that is not badly skewed?

What measures of central tendency and dispersion only become available at the interval/ratio level of measurement?

At Company A employees commute an average of 25 miles and the standard deviation is 10 miles. At Company B employees commute an average of 50 miles and the standard deviation is 5 miles. At which company is there more dispersion in commuting distances?

Which of the following is correct?

Which of the following is a measure of dispersion?

What are three measures of central tendency? What are three measures of dispersion? Make it clear which are which.

Answer the question that follows this SPSS output:   What is the mode? _______________

Answer the questions that follow this SPSS output:   EDUC is an interval/ratio variable that measures number of years of formal schooling completed. This figure describes the scores on EDUC for a group of World War I fiftysomethings and a group of baby boomer fiftysomethings. A) In which group was there more variability in years of schooling completed: the World War I fiftysomethings, the baby boom fiftysomethings, or was the amount of variability within the two groups exactly the same? ____________________ B) Justify your answer in no more than two sentences. Name the statistic(s) that backs up your conclusion and indicate its value(s).

Answer the questions that follow this SPSS output:   A) What is the value of the mode for this variable? __________ B) What is the value of the median for this variable? __________ C) What is the value of the range for this variable? __________ D) What is the value of the 80^th percentile for this variable? __________

The scores on an interval/ratio variable are very positively skewed. Most of the cases on the variable have values _____ the mean. If you are reporting just one measure of central tendency, it should be the _____.