STATISTICAL PROBLEMS

Statistical Problems

Statistical Problems

1. For each case below, choose the most appropriate statistical procedure:

a. A teacher of a low-level reading group is interested in what the average score is for the group of 25 students.

a. Answer:

Mean and median can be used here to find the average score for the group of 25 students

b. An administrator wants to find out if there is a relationship between teacher absences and student achievement.

b. Answer

Correction can be used here as correlation is a statistical tool to measure relationship between two variables. The main result of a correlation is called the correlation coefficient (or "r"). It ranges from -1.0 to +1.0. The closer r is to +1 or -1, the more closely the two variables are related.

If r is close to 0, it means there is no relationship between the variables. If r is positive, it means that as one variable gets larger the other gets larger. If r is negative it means that as one gets larger, the other gets smaller (often called an "inverse" correlation).

While correlation coefficients are normally reported as r = (a value between -1 and +1), squaring them makes then easier to understand. The square of the coefficient (or r square) is equal to the percent of the variation in one variable that is related to the variation in the other. After squaring r, ignore the decimal point. An r of .5 means 25% of the variation is related (.5 squared =.25). An r value of .7 means 49% of the variance is related (.7 squared = .49).

d. A student teacher is interested in finding out the number of students who rate his performance as good, excellent, average, or poor.

d. answer

Total can be use here to find out the number of students who rate his performance as good, excellent, ...