For the following data:
| Size | Mean | Standard deviation | |
| Sample 1 | 4 | 40 | 8 |
| Sample 2 | 5 | 50 | 10 |
The sample statistic t follows t-distribution with 'm' degrees of freedom, then m is equal to
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → 7
For two independent samples, the t statistic for the difference of the means uses the pooled standard deviation, and each sample loses one degree of freedom for its own mean. So the degrees of freedom are
\(m = n_1 + n_2 - 2\)
\(m = 4 + 5 - 2 = 7\)
The means and standard deviations are not needed for the degrees of freedom.
Note: This topic was not in the CUET 2026 syllabus.