Analyze the following results from a paired t-test performed in R.

> require(stats) ## Student's paired t-test >with(sleep, + t. test (extra[group == 1] extra[group == 2], paired = TRUE) ) Paired t-test data: extra [group == 1] and extra [group == 2] t = -4. 0621, df = 9, p-value = 0. 002833 alternative hypothesis: true difference in means is not equal to 0 95 percent confidence interval: -2. 4598858 -0. 7001142 sample estimates : mean of the differences -1. 58