One sample has n = 16 with a SS = 1200 and a second sample has n = 24 and a SS = 1460.
a. Calculate the pooled variance for the two samples
b. Calculate the Estimated Standard of the Mean
Calculate the "t" for both of the following questions using the above data and determine if you Reject Ho or Fail to Reject Ho. Assume a two-tail test, alpha = .05 for both questions below.
c. If the sample mean difference is 4 points, is this enough to reject the null hypothesis? Calculate the t, set the critical boundary, make a decision.
d. If the sample mean difference is 8 points, is this enough to reject the null hypothesis? Calculate the t, set the critical boundary, make a decision.
Calculate the pooled variance for the two samples
Calculate the Estimated Standard of the Mean
If the sample mean difference is 4 points, what is the critical value set for the critical region?
If the sample mean difference is 4 points, what is the calculated t?
If the sample mean difference is 4 points, is this enough to reject the null hypothesis?
If the sample mean difference is 8 points, what is the critical value set for the critical region?
If the sample mean difference is 8 points, what is the calculated t?
If the sample mean difference is 8 points, is this enough to reject the null hypothesis?
A sample of difference scores from a repeated-measures experiment has a mean of MD = 6 with a variance of s2 = 72.
a. If n = 10, is the sample sufficient to reject the null hypothesis using a two-tailed test with alpha = .01?
b. if n = 36, is the sample sufficient to reject the null hypothesis using a two-tailed test with alpha = .01?
If n = 10, what is the standard error of the mean?
If n = 10, what are the critical boundaries for the critical region?
If n = 10, what is the calculated t?
If n = 10, is this sample sufficient to reject the null hypothesis?
If n = 36, what is the standard error of the mean?
If n = 36, what are the boundaries set for the critical region?
If n = 36, what is the calculated t?
If n = 36, is the sample sufficient to reject the null hypothesis?
A researcher would like to demonstrate how different schedules of reinforcement can influence behavior. Two separate groups of rats are trained to press a bar in order to receive a food pellet. One group is trained using a fixed ratio schedule where they receive one pellet for every 10 presses of the bar. The second group is trained using a fixed interval schedule where they receive one pellet for the first bar press that occurs within a 30 second interval. Note that the second group must wait 30 seconds before another pellet is possible no matter how many times the bar is pressed. After 4 days of training, the researcher records the response rate (number of presses per minute) for each rat. The results are summarized as follows:
Fixed Ratio Fixed Interval
n = 10 n = 10
M = 32 M = 26
SS = 90 SS = 110
Do these data indicate that there is a significant difference in responding behavior for these two reinforcement schedules? Test at the .05 level of significance using a two-tail test.
You will use the information in this question to write the Decision in a following question. Please make note of your answers to this question as they are important parts of the Decision.
What is the Independent Variable?
What is the Dependent Variable?
What is the Null Hypothesis?
What is the Alternative Hypothesis?
What are the degrees of freedom for this test?
What are the critical boundaries?
What is the sample standard deviation for the Fixed Ratio group?
What is the sample standard deviation for the Fixed Interval group?
What is the pooled variance?
What is the Estimated Standard Error of the Mean?
What is the calculated t?
What is the decision?
For the first scenario regarding fixed ration/fixed interval reinforcment schedules, what is the decision? Utilizing APA format, please write the brief conclusion paragraph
The following data represent the results from a repeated-measures study comparing two treatment conditions. (IV: treatment; DV: scores)
Treatment
Participant Before Treatment After Treatment D D2
#1 7 13
#2 9 14
#3 11 11
#4 7 14
#5 8 13
#6 10 16
Sample Mean 8.67 13.5
Sample Std. Deviation 1.63 1.64
Do the results indicate a significant difference between the two treatments? Use a two-tailed test with α = .01.
Please make note of your results from this question as you will need the information to prepare the Decision in a subsequent question.
What is the independent variable?
What is the dependent variable?
What is the Null Hypothesis?
What is the Alternative Hypothesis?
What are the degrees of freedom for this test?
What are the critical boundaries?
What is the Mean Difference?
What is the Sum of Squares for the difference scores?
What is the sample variance for the difference scores?
What is the Estimated Standard Error of the Mean for the difference scores?
What is the calcuated t?
Is this sufficient to Reject the Null Hypothesis?