- A sample of size n = 56 has sample mean x = 57.2 and sample standard deviations = 9.1. Part: 0/2 Part 1 of 2 Construct a 99.5% confidence interval for the population mean u. Round the answers to one decimal place. A 99.5% confidence interval for the population mean is Online courses: A sample of 270 students who were taking online courses were asked to describe their overall impression of online learning on a scale of 1-7, with 7 representing the most favorable impression. The average score was 5.81, and the standard deviation was 0.99. Part: 0 / 2 Part 1 of 2 Construct an 80% interval for the mean score. Round the answers to two decimal places. An 80% confidence interval for the mean score is Fake Twitter followers: Many celebrities and public figures have Twitter accounts with large numbers of followers. However, some of these followers are fake, resulting from accounts generated by spamming computers. In a sample of 64 twitter audits, the mean percentage of fake followers was 14.6 with a standard deviation of 10.6. Part: 0/2 Part 1 of 2 Construct a 99.5% interval for the mean percentage of fake Twitter followers. Round the answers to one decimal place. A 99.5% confidence interval for the mean percentage of fake Twitter followers is Sound it out: Phonics is an instructional method in which children are taught to connect sounds with letters or groups of letters. A sample of 133 first graders who were learning English were asked to identify as many letter sounds as possible in a period of one minute. The average number of letter sounds identified was 34.21 with a standard deviation of 23.33. Part: 0 / 2 Part 1 of 2 Construct a 99.9% interval for the mean number of letter sounds identified in one minute. Round the answers to two decimal places. A 99.9% confidence interval for the mean number of letter sounds identified in one minute is