Statistics and Data Analysis Terms - dummies

Statistics and Data Analysis Terms

Focus not only on the terms for the statistics and analyses you’ll calculate but also on their interpretation, especially in the context of a statistics problem. Answer the following problems about different statistics and data analysis terms.

Sample questions

1. Which of the following data sets has a median of 3?

(A) 3, 3, 3, 3, 3

(B) 2, 5, 3, 1, 1

(C) 1, 2, 3, 4, 5

(D) 1, 2, 4, 4, 4

(E) Choices (A) and (C)

Answer: E. Choices (A) and (C) (3, 3, 3, 3, 3; 1, 2, 3, 4, 5)

To find the median, put the data in order from lowest to highest, and find the value in the middle. It doesn’t matter how many times a number is repeated. In this case, the data sets 3, 3, 3, 3, 3 and 1, 2, 3, 4, 5 each have a median of 3.

2. Susan scores at the 90th percentile on a math exam. What does this mean?

Answer: It means that 90% of students who took the exam had scores less than or equal to Susan’s.

A percentile shows the relative standing of a score in a population by identifying the percent of values below that score. Susan scored in the 90th percentile, so 90% of the students’ scores are less than or equal to Susan’s.

3. Suppose that the results of an exam tell you your z-score is 0.70. What does this tell you about how well you did on the exam?