Directions:  Be sure to answer both Problems 1 and 2 by clicking on the tabs at the bottom of the screen.  Answer all problems and submit to instructor at the end of module 3.

 

1.  A random sample is selected from a normal population. The population mean is μ=60 and the population standard deviation is σ=15. After a treatment is given to the members of the sample, the sample mean is M=65. The sample size is n=25.

A) The Hypothesis Test: a=0.05
Ho: μ=60
H1: μ<>60

B) SE[M]

C) Z

D) Is the sample mean sufficient to conclude that the treatment has a significant effect? Give reasons for your decision.

E) If the size of the sample was changed to n = 16, would the sample mean be sufficient to conclude that the treatment has a significant effect? Give reasons for your decision.

 

2.  There were two independent groups who took a school course by different modes. The first sample of students took the course in the online and the second sample took the course in the conventional face to face mode. Using the sample data determine if there is significant difference in the scores between the two groups.

 

A) SE[M1-M2]          

 

B) t-score       

 

C) Are the two sample means sufficient to conclude that the educational modes are significantly different?  Give reasons for your decision.

 

Since the t-score falls into the critical region (4 > 2.01) I reject the null hypothesis.  There is a significant difference between the two methods of teaching.