Question

Emergency rooms have reason to suspect that visits increase on the weekends. A recent report indicates that Monday through Thursday represent 10% per day of the weekly total visits while Friday accounts for 15%, Saturday 25% and Sunday 20%. If your ER has the following pattern, Monday, 120, Tuesday, 130, Wednesday 110, Thursday 95, Friday 160, Saturday 280 and Sunday 105.

Does your facility have the same pattern as the recent report at the 10% level?

	1.	Yes
	2.	No

Answer 1

Chi square test for Goodness of fit

Ho: facility have the same pattern as the recent report

H1: facility do not have the same pattern as the recent report

expected frequncy,E = expected proportions*total frequency

total frequency=1000

category	observed frequencey, O	expected proportion	expected frequency,E			(O-E)²/E
Monday	120	0.10	100			4.000
Tuesday	130	0.10	100			9.000
Wednesday	110	0.10	100			1.000
Thursday	95	0.10	100			0.250
Friday	160	0.15	150			0.667
Saturday	280	0.25	250			3.600
Sunday	105	0.20	200			45.125

chi square test statistic,X² = Σ(O-E)²/E =63.642    

  

level of significance, α=0.1

Degree of freedom=k-1=7-1=6

  

P value =0.0000                                [ excel function: =chisq.dist.rt(test-stat,df) ]

Decision: P value < α,          Reject Ho

so, answer is NO

no, facility do not have the same pattern as the recent report at the 10% level