A test is conducted to compare three different income tax so
A test is conducted to compare three different income tax software packages to determine whether there is any difference in the average time it takes to prepare income tax returns using the three different software packages. Ten different persons\' income tax returns are done by each of the three software packages and the time is recorded for each. The computer results are shown below.
ANOVA
Based on these results and using a 0.05 level of significance which is correct regarding blocking?
| SUMMARY | Count | Sum | Average | Variance |
| 1 | 3 | 9 | 3 | 1 |
| 2 | 3 | 30 | 10 | 1 |
| 3 | 3 | 12 | 4 | 0 |
| 4 | 3 | 6.5 | 2.166667 | 0.583333 |
| 5 | 3 | 25 | 8.333333 | 2.333333 |
| 6 | 3 | 7 | 2.333333 | 1.083333 |
| 7 | 3 | 10 | 3.333333 | 0.333333 |
| 8 | 3 | 18 | 6 | 1 |
| 9 | 3 | 33.5 | 11.16667 | 0.583333 |
| 10 | 3 | 4.5 | 1.5 | 0.25 |
| Software A | 10 | 47.5 | 4.75 | 12.95833 |
| Software B | 10 | 47.5 | 4.75 | 10.79167 |
| Software C | 10 | 60.5 | 6.05 | 13.46944 |
Solution
Please note that your guess for answer A is wrong due to this reason.
p value = 1.6E-14 = 1.6x10-14
Thus 1.6 as such is not p value but significant digit in p value which is very small with more than 10 decimal digits.
Hence 1.6x10-14<0.05, we reject null hypothesis.
There is significant difference between blocks.
Blocking was effective because p-value = 1.6E-14 is less than 0.05. is right answer.
