Question

A sample of 200 individuals are tested for their blood type is given in the first table, and the results are used to test the hypothesized distribution of blood types. The observed results are given in the second table. At the .05 level of significance, is there sufficient evidence to show that the stated distribution is incorrect?

Blood Type	  A  Â	  B  Â	  O  Â	  AB  Â
Percent	0.4	0.08	0.4	0.12

Blood Type	  A  Â	  B  Â	  O  Â	  AB  Â
Number	68	15	87	30

(a) Find the test statistic. (Give your answer correct to two decimal places.)


(ii) Find the p-value. (Give your answer bounds exactly.)
< p <
(b) State the appropriate conclusion.

Reject the null hypothesis, there is significant evidence that the stated distribution is incorrect. Reject the null hypothesis, there is not significant evidence that the stated distribution is incorrect.     Fail to reject the null hypothesis, there is significant evidence that the stated distribution is incorrect. Fail to reject the null hypothesis, there is not significant evidence that the stated distribution is incorrect.

Answer 1

(a) The test statistic is 3.98.

(ii) The p-value is 0.2642.

(b) Fail to reject the null hypothesis, there is not significant evidence that the stated distribution is incorrect.

observed	expected	O - E	(O - E)² / E
68	80.000	-12.000	1.800
15	16.000	-1.000	0.063
87	80.000	7.000	0.613
30	24.000	6.000	1.500
200	200.000	0.000	3.975
3.98	chi-square
3	df
.2642	p-value

Please give me a thumbs-up if this helps you out. Thank you!