Question

"Contingency table below; Calculate the Chi^2 value"

Please include Excel functions or calculations if possible.

Result	Mon.	Tues.	Wed.	Thurs.	Fri.
Number of defective parts	13	7	9	10	14	53
Number of acceptable parts	85	93	93	91	106	468
Totals	98	100	102	101	120	521

Answer 1

Solution:

Test statistic formula is given as below:

Chi square = ∑[(O – E)^2/E]

Where, O is observed frequencies and E is expected frequencies.

E = row total * column total / Grand total

Calculation tables for test statistic are given as below:

Observed Frequencies
	Day
Result	Mon	Tues	Wed	Thurs	Fri	Total
# defective parts	13	7	9	10	14	53
# acceptable parts	85	93	93	91	106	468
Total	98	100	102	101	120	521

Expected Frequencies
	Day
Result	Mon	Tues	Wed	Thurs	Fri	Total
# defective parts	9.96929	10.17274	10.3762	10.27447	12.20729	53
# acceptable parts	88.03071	89.82726	91.6238	90.72553	107.7927	468
Total	98	100	102	101	120	521

Calculations by using excel
(O - E)
3.03071	-3.17274	-1.3762	-0.27447	1.792706
-3.03071	3.172745	1.3762	0.274472	-1.79271

(O - E)^2/E
0.92135	0.989537	0.182526	0.007332	0.263269
0.104341	0.112063	0.020671	0.00083	0.029815

Test Statistic = Chi square = ∑[(O – E)^2/E] = 2.631733

χ2 statistic = 2.631733