Question

SCENARIO 12-7

Data on the percentage of 200 hotels in each of the three large cities across the world on whether minibar charges are correctly posted at checkout are given below.

​	Hong Kong New York Paris
Yes No	86% 76% 78% 14% 24% 22%

At the 0.05 level of significance, you want to know if there is evidence of a difference in the proportion of hotels that correctly post minibar charges among the three cities.


Referring to Scenario 12-7, the expected cell frequency for the Hong Kong/Yes cell is ________.

Answer 1

SCENARIO 12-7

Data on the percentage of 200 hotels in each of the three large cities across the world on whether minibar charges are correctly posted at checkout are given below.

​	Hong Kong New York Paris
Yes No	86% 76% 78% 14% 24% 22%

At the 0.05 level of significance, you want to know if there is evidence of a difference in the proportion of hotels that correctly post minibar charges among the three cities.

Percentages are given. We convert to actual frequencies to compute chi square.

Chi-Square Test
Observed Frequencies
	Column variable					Calculations
Row variable	Hongkong	Newyork	Paris	Total		fo-fe
Yes	172	152	156	480		12	-8	-4
No	28	48	44	120		-12	8	4
Total	200	200	200	600
Expected Frequencies
	Column variable
Row variable	Hongkong	Newyork	Paris	Total		(fo-fe)^2/fe
Yes	160	160	160	480		0.9	0.4	0.1
No	40	40	40	120		3.6	1.6	0.4
Total	200	200	200	600
Data
Level of Significance	0.05
Number of Rows	2
Number of Columns	3
Degrees of Freedom	2
Results
Critical Value	5.991
Chi-Square Test Statistic	7
p-Value	0.0302
Reject the null hypothesis

Calculated chi square =7.0 which is > critical chi square 5.991. Ho is rejected.

There is enough evidence of a difference in the proportion of hotels that correctly post minibar charges among the three cities.

Referring to Scenario 12-7, the expected cell frequency for the Hong Kong/Yes cell is 160