Posted by **jeen** on Monday, November 29, 2010 at 1:36pm.

Q. The MBA department is concerned that dual degree students may be receiving lower grades than the regular MBA students. Two independent random samples have been selected. 100 observations from population 1 (dual degree students) and 100 from population 2 (MBA students). The sample means obtained are X1(bar)=84 and X2(bar)=87. It is known from previous studies that the population variances are 4.0 and 5.0 respectively. Using a level of significance of .10, is there evidence that the dual degree students are receiving lower grades? Fully explain your answer.

Ans.

To Test

Ho : μ1= μ2 Vs H1 : μ1< μ2 (one tailed test)

Test Statistics: As n is large >30 so we use Normal Test

follows Standard Normal distribution N(0,1)

= -10

Putting

=84 =87 n1=100 n2=100 =4 =5 we get

P-value = P (z < -10) = 0

Since the P-value 0 < 0.1, we reject H0. It is statistically significant.

Conclusion

At the 10% level of significance, the data provides enough evidence to reject the null hypothesis. Thus we conclude at 0.1 level of significance that the dual degree students are receiving lower grades