Chapter 8 Confidence Intervals (Mean) Ill-"4 answered I 1 A researcher is interested in finding a 90% confidence interval for the mean number minutes students are concentrating on their professor during a one hour statistics Lecture. The study included 9? students who averaged 36.5 minutes concentrating on their professor during the hour lecture. The standard deviation was \"12.6 minutes. Round answers to 3 decimal places where possible. a. To compute the confidence interval use a distribution. b. With 90% confidence the population mean minutes of concentration is between and I 'minutes. c. If manyr groups of 9? randomly.r selected members are studied, then a different confidence interval would be produced from each group. About percent of these confidence intervals will contain the true population mean minutes of concentration and about percent will not contain the true population mean minutes of concentration. . rl Chapter 8 Confidence Intervals (Mean) D.-"4 answered I 2 1' C I? A psychiatrist is interested in finding a 9(196 confidence interval for the tics per hour exhibited by children with Tourette syndrome. The data below show the tics in an observed hour for 14 randomly selected children with Tourette syndrome. Round answers to 3 decimal places where possible. nun-\"mun a. To compute the condence interval use a distribution. b. With 90% confidence the population mean number of tics per hour that children with Tourette syndrome exhibit is between land | l. c. If many groups of 14 randomly selected children with Tourette syndrome are observed, then a different confidence interval would be produced from each group. About percent of these confidence intervals will contain the true population mean number of tics per hour and about percent will not contain the true population mean number of tics per hour. Chapter 8 Confidence Intervals (Mean) 1/4 answered 3