Answer:
There is significant preference among the 3 designs
Step-by-step explanation:
Given :
Design 1 Design 2 Design 3
54 38 28
H0 : no significant preference among the 3 designs
H1 : The preference among the designs are different
To test, we use the Chisquare test for independence ;
χ² = (observed - Expected)² / Expected
The sample size, n = 120
Expected = 120 / number of designs = 120 / 3 = 40
(54-40)^2/ 40 + (38 - 40)² / 40 + (28 - 40)² / 40
= 4.9 + 0.1 + 3.6
= 8.6
The Chisquare critical value at 95% = 5.99
Since ;
|χ² critical| < χ² statistic ; we reject the null and conclude that there is significant preference among the 3 designs