Question

18. Write a short summary of the information presented.

H: A lower percentage of people who wear wristwatches than people who don’t wear wristwatches arrive late for appointments.

H₀: An equal percentage of people who do and who do not wear wristwatches arrive late for appointments.

		Was the subject late for the appointment?
			No	Yes	Σ
	Was subject wearing	No	121	73	194
	a wristwatch?	Yes	195	61	256
	Σ	298.39	316	134	450

χ_calc² = 10.05

_.₀₅χ₁² = 3.84

Answer 1

18)

Here we are testing whether a lower percentage of people who wear wristwatches than people who don’t wear wristwatches arrive late for appointments.

The chi-square test statistic is given by:

where Observed values are given to us and expected values are calculated using,

Expected frequency = [(Row total) x (Column total)] / Table total

Also, the critical value is 3.84

Since the test statistic value is greater than the critical value, so we have sufficient evidence to reject null hypothesis H0. Thus, we can say that a lower percentage of people who wear wristwatches than people who don’t wear wristwatches arrive late for appointments.