URGENT PLS HELP 200 cross-country runners were surveyed about how many hours they spend per week training. The mean was 12 hours per week and there was a standard deviation of 2 hours per week. How many cross-country runners spend between 10 and 16 hours a week in training?

9.4.34  question   to estimate the height of a stone  figure, an observer holds a small square up to her eyes and walks backward from the figure. she stops when the bottom of the figure aligns with the bottom edge of the  square, and when the top of the figure aligns with the top edge of the square. her eye level is 1.811.81 m from the ground. she is 3.703.70 m from the figure. what is the height of the figure to the nearest hundredth of a  meter?

Can someone, me with this.i really need with this

How can you find the magnitude of a vector, v = < x,y > , where the horizontal change is x and the vertical change is y?