If n is the sample size of the population, then degree of freedom in t-distribution is

Degree of freedom represents how many values are free to vary in a dataset.

When working with n data points in a sample, (n-1) values can change freely, but the last value is fixed to maintain the sample mean.

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Consider a sample with n observations. When calculating the sample mean, one degree of freedom is used.

Remaining degrees of freedom = n - 1

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For example, if 5 students have an average score of 60:

Sample size n = 5

If four scores are: 50, 60, 70, 80

The fifth score must be 40 to maintain the average of 60.

The fifth value cannot vary freely.

Degrees of freedom = 5 - 1 = 4

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For t-distribution:

Degrees of Freedom (df) = n - 1

where n = sample size

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Option 1 (n): Incorrect. Does not account for the constraint imposed by calculating the mean.

Option 2 (2n): Incorrect. No statistical basis for this value.

Option 3 (n+1): Incorrect. A degree of freedom is lost, not gained.

Option 4 (n-1): Correct. This is the standard formula for degrees of freedom in t-distribution.

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The degree of freedom in t-distribution = n - 1

Answer: Option 4: n-1