Yuri computes the mean and standard deviation for the sample data set 12, 14, 9, and 21. he finds the mean is 14. his steps for finding the standard deviation are below. what is the first error he made in computing the standard deviation

I'm marking the brainliest and it's 15 points

Tom travels between the two mile markers shown and then finds his average speed in miles per hour. select the three equations that represent this situation.

A) find the derivative of the inverse to f(x) = 3x + sint at x 6. b) (cale) find the derivative of the inverse to f(x)+3sin at x 6. if x +2y -34, ind he behaviar of the cure at 4,.3), c) a. increasing, concave up d. decreasing, concave down b. increasing, concave down e. decreasing, inflection point c. decreasing, concave up