answer please these

Suppose you scored 90, 79, 86, and 77 on your four exams in a mathematics course. Calculate the range and standard deviation of your exam scores. Round the mean to the nearest tenth to calculate the standard deviation The range of the exam scores is |. (Simplify your answer.) The standard deviation of the exam scores is . (Round to two decimal places as needed.)For the following set of numbers, find the mean, median, mode and midrange. 12, 12, 13, 14, 16, 16, 16, 17, 28 The mean is The median is Select the correct choice below and fill in any answer boxes within your choice. O A. The mode is (Use a comma to separate answers as needed.) O B. There is no mode. The midrange is