Suppose you scored 80​, 90​, 72​, and 78 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
Standard deviation

Shryia read a 481 -page-long book cover to cover in a single session, at a constant rate. after reading for 1.5 hours, she had 403 pages left to read. how fast was shryia reading? pages per hour how long did it take her to read the entire book? hours plz i realy need this

Enter the missing numbers in the boxes to complete the table of equivalent ratios of lengths to widths. ? 18 8 ? 10 30 12 ?

What situation is an example of an observational study