# Assignment: Correlation

This is an exercise in collecting data, calculating Pearson’s r correlation coefficient, and presenting your results.

You will work on this assignment with a group.  With your group you will design a correlation study.

The study you design may be related to education, although that is not required. You will collect the data with your group. Each person should collect data from 10 subjects. With your group you would have data for 40 subjects (4 X 10).

With your group write your research question and the appropriate null and alternative hypotheses.

Individually (each group member does this independent of each other), using Excel spreadsheet, enter the data from you and your group, create a scatterplot, and calculate Pearson’s r correlation coefficient. Determine whether the correlation coefficient is statistically significant at the .05 alpha level by checking it on the correlation critical value table. Print your Excel spreadsheet (which contains data, spreadsheet, and scatterplot) along with your word processing file that contains your research question, null and alternative hypothesis, definition of terms, and answer to the research question. A sample assignment has been provided below.

Sample Assignment

Research Question: Is there a statistically significant relationship between height and arm span of students in grades three, four, and five at Garfield School? (1 point)

Null Hypothesis: There is no statistically significant relationship between height and arm span of students in grades three, four, and five at Garfield School (1 point)

Alternatiave Hypothesis: There is a statistically significant relationship between height and arm span of students in grades three, four, and five at Garfield School. (1 point)

Defintion of Terms:
Height–Distance in centimeters from the bottom of the heel to the top of the head of a student standing barefooted. (1 point)
Span–Distance in centimeters between the tips of the middle fingers as measured across the back of a standing student with outreached arms that are parallel to the floor. (1 point)

Answer: There was a statistically significant relationship between height and arm span of students in grades three, four, and five at Garfield School, r (98) = .99 , p < .05. (1 point for statement, 1 point for italicizing r), 1 point for correct degrees of freedom in parentheses, 1 point for correct correlation coefficient value, 1 point for italicizing p, and 1 point for correct sign [< or >] with p value). (1 point for scatterplot from Excel)