Mean of Roller Coaster Speeds: Listed are maximum speeds (in km/h) of randomly selected roller coasters in the United States. 70, 76, 97, 81, 57, 151, 194, 65, 117, 65, 45, 105. Find the mean. Find the median. Find the mode. What is the variance? Hint for 4: The solution for #4 is available in the eBook. Also see section 3.2 for the sample standard deviation formula.