The items produced in a factory have four types of defects T

The items produced in a factory have four types of defects. Test at significance level of 5% if the type of defect is independent of the shift during which the defective item is produced. A random sampling of defective items gave the following results.

Solution

H0: the number of defects is independent of the shift

H1: the number of efects depends on the shift

we use chi square contingency table here

Since p value is greater than 0.05, we accept the null hypothesis.

Chi-square Contingency Table Test for Independence
			Col 1	Col 2	Col 3	Col 4	Col 5	Total
	Row 1		1	10	60	35	20	126
	Row 2		2	12	50	47	25	136
	Row 3		3	20	65	40	32	160
	Total		6	42	175	122	77	422
			7.28	chi-square
			8	df
			.5067	p-value