In Google Sheets, the CONFIDENCE.T function is used to calculate the confidence interval for a population mean, assuming a t-distribution. It takes into account the sample size and the standard deviation as parameters.

The syntax for the CONFIDENCE.T function is as follows:

CONFIDENCE.T(alpha, standard_deviation, size)

alpha: This represents the significance level used to determine the confidence level. It is the probability of observing a sample mean within the confidence interval. Common values are 0.05 (95% confidence) and 0.01 (99% confidence).

standard_deviation: This is the standard deviation of the population.

size: This parameter represents the sample size.

The CONFIDENCE.T function returns the margin of error, which is the range around the sample mean within which the true population mean is likely to be. The confidence interval can be calculated by adding and subtracting the margin of error from the sample mean.

The CONFIDENCE.T function assumes a t-distribution, which is appropriate when working with small sample sizes and the population standard deviation is unknown. It is important to note that as the sample size increases, the t-distribution approaches the normal distribution, and in such cases, the CONFIDENCE.NORM function can be used instead.