Statistical Methods (EDUC 201) ACTIVITY 4
HYPOTHESIS-TESTING Instruction: Apply the five steps of hypothesis-testing procedure to each problem below.
1. A researcher conducted an experiment to determine the effect of a lecturer’s age on
student preferences to hear him lecture. In a regular classroom situation, 20 students were told that the administration wished to know their preferences regarding a forthcoming visiting lecturer series. In particular, they were asked to evaluate a professor who “might be visiting the campus.” The professor was described to all students in the same way with one exception: One-half of the students were told the professor was 65 years old: One-half were told the professor was 25 years old. All students were then asked to indicate their willingness to attend the professor’s lecture (higher scores indicates greater willingness). The following results were obtained:
(Scores of the Students Told Professor Was 25 years old)
X1 65 38 52 71 69 72 55 78 56 80
(Scores of Students Told Professor Was 65 years old)
X2 78 42 77 50 65 70 55 51 33 59
Problem 1 X1 = Professor is 25 years old X1 65 38 52 71 (X1)2 4,225 1,444 2,704 5,041 (x1 – x ) 1.4 -25.6 -11.6 7.4 (x1 – x)2 1.96 655.36 134.56 54.76
69 72 55 78 56 80 ∑ = 636 x = 63.6 X1 = 63.6
4,761 5,184 3,025 6,084 3,136 6,400 ∑(X1)2 = 42,004
5.4 8.4 -8.6 14.4 -7.6 16.4 ∑=0
29.16 70.56 73.96 207.36 57.76 268.96 ∑(x1 – x)2= 1,554.40
s2 = n (∑x12) – (∑x1)2 n (n-1) s2 = 10(42,004) – 9636)2 10 (10 - 1) s2 = s2 = 420,040 – 404,496 10(9) (15,544) 90
s = √ s2 s = √172.7111111 s = 13.14195994 s = 13.142
s2 = 172.7111111 s2 = 172.711
Submitted by: Pauline Ferrero MAT-LL Southwestern University 1st Sem 2009