In: Statistics and Probability
Using the below data I need a statistical formula to show which of these categories a total of 50 people did the best in in a memory test of words vs. pictures vs. numbers or if it is statistically not able to be proven "reject the null hypothesis"
Words Out of 20 Male & Female N=50 | Pictures out of 18 Male & Female N=50 | Numbers out of 18 Male & Female N=50 |
Words | Pictures | Numbers |
16 | 17 | 12 |
15 | 16 | 12 |
17 | 15 | 11 |
14 | 16 | 14 |
17 | 14 | 14 |
16 | 17 | 16 |
17 | 14 | 8 |
14 | 16 | 9 |
19 | 17 | 15 |
10 | 9 | 15 |
12 | 16 | 13 |
14 | 15 | 12 |
11 | 14 | 9 |
11 | 14 | 10 |
14 | 15 | 17 |
11 | 13 | 14 |
13 | 13 | 12 |
13 | 13 | 12 |
12 | 16 | 12 |
15 | 17 | 11 |
11 | 14 | 10 |
16 | 16 | 10 |
12 | 13 | 16 |
12 | 9 | 8 |
9 | 11 | 11 |
341 | 360 | 303 totals |
6.82 | 7.2 | 6.06 mean |
2.564 | 2.2546 | 2.5219 Std. Deviation |
here we use one-way anova with
null hypothesis H0: all three groups mean are equal
alternate Hypothesis Ha: atleast one group mean is different from other
since p-value between groups is less than typical alpha=0.05, so we reject H0 and conclude that atleast one group mean is different from other.
( here number of observation in each of the group is 25 accordingly analysis has been done, if it is different please revert back at earliest)
following information has been generated using ms-excel
Anova: Single Factor | ||||||
SUMMARY | ||||||
Groups | Count | Sum | Average | Variance | ||
Column 1 | 25 | 341 | 13.64 | 6.573333 | ||
Column 2 | 25 | 360 | 14.4 | 5.083333 | ||
Column 3 | 25 | 303 | 12.12 | 6.36 | ||
ANOVA | ||||||
Source of Variation | SS | df | MS | F | P-value | F crit |
Between Groups | 67.38667 | 2 | 33.69333 | 5.610361 | 0.00544 | 3.123907 |
Within Groups | 432.4 | 72 | 6.005556 | |||
Total | 499.7867 | 74 |
if number of observation is 50 then following information has been generated and found the p-value is more than typical alpha=0.05, so we accept H0 ( fail to reject H0)
within SS | between SS | ||||||
Group | nj | mean(xj-) | s2 | nj*xj- | (n-1)s2 | (xj--x-) | nj(xj--x-)2 |
1 | 50 | 6.82 | 6.5733 | 341 | 322.0917 | 0.126667 | 0.80222222 |
2 | 50 | 7.2 | 5.0833 | 360 | 249.0817 | 0.506667 | 12.8355556 |
3 | 50 | 6.06 | 6.36 | 303 | 311.64 | -0.63333 | 20.0555556 |
sum | 150 | 20.08 | 18.0166 | 1004 | 882.8134 | 0 | 33.6933333 |
grand mean(x-) | 6.693333 | ||||||
ANOVA | |||||||
SOURCE | DF | SS | MS | F | CRITICAL F(0.05) | p-value | |
BETWEEN | 2 | 33.69 | 16.84667 | 2.81 | 3.06 | 0.063737 | |
WITHIN(ERROR) | 147 | 882.81 | 6.005533 | ||||
TOTAL | 149 | 916.51 |