In: Statistics and Probability
Chi-Square Goodness of Fit Test (how your work) (NO HAND WRITING ITS HARD TO READ)
A researcher has four prototypes for a small Unmanned Aerial System controller and wants to know which one that users prefer. The researcher asks 120 participants to use each controller and annotate which one they liked best. At the conclusion of the study, the researcher hopes to have a clearly identified prototype that is best preferred among the four. The table below represents the number of times each prototype was chosen by the participants.
Prototype A |
Prototype B |
Prototype C |
Prototype D |
14 |
34 |
61 |
11 |
H0: Null Hypothesis: There is no preferred prototype
HA: Alternative Hypothesis: There is preferred prototype
The Test Statistic is:
Decision Rule:
Take = 0.05
df = 4 - 1 = 3
By Technology, critical value of = 7.815
Reject null hypothesis if > 7.815
Test Statistic is got as follows:
Prototype | Observed (O) | Expected (E) | (O - E)2/E |
Prototype A | 14 | 30 | 8.5333 |
Prototype B | 34 | 30 | 0.5333 |
Prototype C | 61 | 30 | 32.033 |
Prototype D | 11 | 30 | 12.033 |
Total = | 53.133 |
So,
Test Statistic = 53.133
Since calculated value of = 53.133 is greater than critical value of = 7.815, the difference is significant. Reject null hypothesis.
Conclusion:
The data support the clam that there is preferred prototype.