The t-value in the above data refers to the statistical significance of the regression coefficient for the predictor variable “Carat”. It measures the ratio of the estimated coefficient to its standard error, and indicates whether the coefficient is significantly different from zero (i.e. whether it has a significant effect on the outcome variable). In this case, the t-value for “Carat” is 183.004, which is very large and highly significant (p < 0.001), indicating that carat has a strong positive effect on the outcome variable.