In: Statistics and Probability
The following data were collected from a repeated-measures study:
Determine if there are any significant differences among the four treatments. Use a .05 level of significance.
Remember to;
1) State the null hypothesis,
2) Show all of your calculations,
3) Make a decision about your null hypothesis,
4) Make a conclusion including an APA format summary of your findings (include a measure of effect size if necessary), and
5) Indicate what you would do next given your findings.
Participant |
Treatments |
||||
A |
B |
C |
D |
||
∑X2 = 332 G = 60 |
1 2 3 4 |
6 4 4 10 |
3 4 2 7 |
3 2 0 7 |
0 2 2 4 |
T = 24 SS = 24 |
T = 16 SS = 14 |
T = 12 SS = 26 |
T = 8 SS = 8 |
1)
Ho: µ1=µ2=µ3=µ4
H1: not all means are equal
2)
treatment | A | B | C | D | ||
count, ni = | 4 | 4 | 4 | 4 | ||
mean , x̅ i = | 6.000 | 4.00 | 3.00 | 2.00 | ||
std. dev., si = | 2.828 | 2.160 | 2.944 | 1.633 | ||
sample variances, si^2 = | 8.000 | 4.667 | 8.667 | 2.667 | ||
total sum | 24 | 16 | 12 | 8 | 60 | (grand sum) |
grand mean , x̅̅ = | Σni*x̅i/Σni = | 3.75 | ||||
square of deviation of sample mean from grand mean,( x̅ - x̅̅)² | 5.063 | 0.063 | 0.563 | 3.063 | ||
TOTAL | ||||||
SS(between)= SSB = Σn( x̅ - x̅̅)² = | 20.250 | 0.250 | 2.250 | 12.250 | 35 | |
SS(within ) = SSW = Σ(n-1)s² = | 24.000 | 14.000 | 26.000 | 8.000 | 72.000 |
no. of treatment , k = 4
df between = k-1 = 3
N = Σn = 16
df within = N-k = 12
mean square between groups , MSB = SSB/k-1 =
11.6667
mean square within groups , MSW = SSW/N-k =
6.0000
F-stat = MSB/MSW = 1.9444
P value = 0.1763
3)
p-value>α , do not reject null hypothesis
4)
there is no significant difference among means of different treatment F(3,12) = 1.94,p>0.10
5) there is no steps will be taken forward because null hypothesis is not rejected