What does || u + v || mean?

Carl's candies has determined that a candy bar measuring 3 inches long has a z-score of +1 and a candy bar measuring 3.75 inches long has a z-score of +2. what is the standard deviation of the length of candy bars produced at carl's candies?

Johnny rode his bike to a friends house 4 blocks down the street in his neighborhood. he immediately rode back home once he realized his friend was unable to play. what was his displacement for the total bike ride trip? what could you use as a reference point ? show the steps to solve this problem.

12 3 4 5 6 7 8 9 10 time remaining 42: 01 ryan gathered data about the age of the different dogs in his neighborhood and the length of their tails. which best describes the strength of the correlation, and what is true about the causation between the variables?