Question

Henry Watson, Inc., a designer and installer of industrial signs, employs 120 people. The company recorded the type of the most recent visit to a doctor by each employee. Here are the results:

Visit Type	Number of Visits
Primary care	80
Medical specialist	17
Surgical specialist	15
Emergency	8
	120

A national assessment conducted in 2017 found that 74% of all physician visits were to primary care physicians, 12% to medical specialists, 8% to surgical specialists, and 6 % to emergency departments. Test at the .05 significance level if Henry Watson employees differ significantly from the survey distribution. (15 pts)

Answer 1

The null and alternative hypothesis

H0: There is no significant difference between Henry Watson employees physician visit and survey distribution.

Ha: There is significant difference between Henry Watson employees physician visit and survey distribution.

Test statistic

where Oi : observed frequency

Ei : expected frequency

Let us calculate chi square

	Oi	Ei	(Oi-Ei)^2/Ei
Primary	80	120*0.74= 88.8	0.87207
Medical	17	120*0.12 = 14.4	0.46944
Surgical	15	120*0.08= 9.6	3.0375
Emergency	8	120*0.06 = 7.2	0.08889
Total	120		4.4679

Therefore

degrees of freedom = 4-1=3

P value = 0.2152

Since P value > significant level

The result is not significant

Fail to reject H0

At 0.05 level , there is not sufficient evidence to conclude that there is significant difference between Henry Watson employees physician visit and survey distribution.