How many weeks of data must be randomly sampled to estimate the mean weekly sales of a new line of athletic footwear? We want a 95% confidence interval that the sample mean is within 3299 of the population mean. The population standard deviation is presumed to be 51299. The number of weeks is: (la. 11 L) b. 139 (:3 c. 12 (:3 d. 138 C 3 e EDD C 3 f 1200 A social media analyst conducts a study on the proportion of people who make at least one post per day. She found a confidence interval estimate of U.\"l13