This should be the result of regression function in matlab. It is said that the confidence interval of B2 contains 0 because the confidence interval of B2 is [-7.4989 to 0. 1077], which contains 0, and the value on the right is 0. 1077, which is very close to 0, so B2 is likely to take a value close to 0. If B2 takes a value close to 0,