Sean has taken three exams and earned scores of 89, 70, and 81 out of a possible 100 points. He needs an average of at least to earn a B in the course. What range of scores on the fourth (and last) 100-point test will guarantee a B in the course? The range of scores on the fourth (and last) 100-point test is ___ to ___. The height h of an object thrown from the top of a ski lift feet high after t seconds is h= -16t^2+32t+1684. For what times is the height of the object at least 1300 feet? The height of the object is at least feet from ___ seconds to ___ seconds.