An e-business manager wants to use the Normal z distribution to estimate the average browsing time of potential cutomers, visiting a certain website. The value of the standard deviation of all browsing times is known. To construct a 80% confidence interval the e-business manager originally selected a random sample of 50 browsing times, and then increased the sample size to 80. Choose the correct statement. 0 The confidence interval became longer. 0 There is no relation between the length of the confidence interval and the sample size. 0 The confidence interval didn't change. 0 The confidence interval became shorter. 0 None of the above