This document provides information to calculate the t-value and standard deviation for a t-test. It gives sample data with two variables, X1 and X2, for 11 observations. It then shows the calculations to find the mean for X1 and X2, the differences from the means, and the sums of squares. The standard deviation is calculated as the square root of the sum of squares divided by the degrees of freedom. Finally, the t-value is calculated as the difference between the means divided by the standard deviation times the square root of the sample size. The t-value is closest to 1.895.