Answer
a) $\mu$ is between 233.4sec and 256.65 sec. b) The best point estimate is 245.025 and the margin of error is 11.625.
Work Step by Step
a) According to the screen the confidence interval is (233.4,256.65), which is: $\mu$ is between 233.4sec and 256.65 sec. b) The best point estimate of $\mu$ according to the screen is 245.025 and the margin of error is:$\frac{upper \ confidence \ limit-lower \ confidence \ limit}{2}=\frac{256.65-233.34}{2}=11.625$