The following are randomly selected scores in General Mathematics of ten Grade 11 students 75 81 65 83 80 76 85 70 77 68 A) Find the 98% confidence interval for the mean score of all the Grade 11 students, assuming that the students' score is approximately normally distributed B) Find the lower and upper confidence limit

The following observations are lifetimes (days) subsequent to diagnosis for individuals suffering from blood cancer. 116 181 461 517 739 743 789 865 255 984 1357 419 441 1026 1063 1166 1369 1408 1455 1479 1063 924 1290 1191 1222 1222 1277 1519 1578 1578 1899 1926 1966 1603 1605 1696 1735 1799 1815 1852 807 1252 1599 (a) Can a confidence interval for true average lifetime be calculated without assuming anything about the nature of the lifetime distribution? Explain your reasoning. [Note: A normal probability plot of the data exhibits a reasonably linear pattern.] Yes, the range is sufficiently large enough for the confidence interval to be reasonable. No, we need to assume that the population is normally distributed. No, the sample size is not large enough for the confidence interval to be reasonable. Yes, the sample size is large enough for the confidence interval to be reasonable. No, the range is not large enough for the confidence interval to be reasonable. (b) Calculate and…

#9).

A researcher is interested in finding a 90% confidence interval for the mean number of times per day that college students text. The study included 97 students who averaged 25.5 texts per day. The standard deviation was 20.5 texts. Round answers to 3 decimal places where possible. b. With 90% confidence the population mean number of texts per day is between ______ and _______  texts. c. If many groups of 97 randomly 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 number of texts per day and about ___________ percent will not contain the true population mean number of texts per day.