The linear correlation between violent crime rate and percentage of the population that has a cell phone is minus−0.918 for years since 1995. do you believe that increasing the percentage of the population that has a cell phone will decrease the violent crime rate? what might be a lurking variable between percentage of the population with a cell phone and violent crime rate?

Anew obstacle course is home to several new types of challenging obstacles. one such obstacle is traversing a 15-stair staircase. to make it more challenging, the stairs are not uniformly spaced. rather, the vertical space between consecutive stairs for the first 10 stairs is 113 feet and the vertical space for the last 5 stairs is 134 feet. what is the total vertical distance traveled ascending and descending the entire 15-stair staircase?