When you have two groups with information it may be worthwhile to get better understanding of their differences.
In this case, we are going to compare two groups of underweight newborns who were provided with different types of treatment programs (called program A and program B). Our goal is to examine differences in discharge weight between the groups.
a. Go to http://graphpad.com/quickcalcs/ttest1.cfm?Format=SD Under the option "Choose Data Entry Format" pick the option "Enter mean, SD, and N" (SD=std.deviation, N=sample size) under "Enter Data" enter the labels for group A and B, and their means, standard deviation and sample sizes.
NOTE: We are providing you with ranges- PLEASE ENTER A NUMBER WITHIN THE RANGE.
(Not lower and not greater. But, you can pick any random number you want... i.e. between 9-10.5 you can pick 9, 9.25, 9.333, etc...NO TWO STUDENTS SHOULD HAVE THE EXACT SAME NUMBERS)
The results for group A are: Mean 9-10.5, SD 1.1-1.5, N 47-51
The results for group B are: Mean 10-11.8 SD 0.8-1.3 N 43-48
b. What is the confidence interval for the differences between the groups? Does it contain the null hypothesis in the range?
c. Do you conclude that one program is better than another program? If so, state which one and explain how you have reached that conclusion. If not, please show what is the evidence that led you to that conclusion as well.
d. As the standard error of the differences increases, what would happen to the T value?
SELECT ONE: Increase/Decrease/Will not Change.
* What would make the standard error change?
* Try to conduct this action on the calculator and change the T value. Then, take a look at the standard error of the differences.