Scott paddles a canoe upstream in 4 hours, then returns downstream in 1 hour. If the river flows at 3 miles per hour, then what would Scott's paddling speed be in calm water?

Assume that the weights of quarters are normally distributed with a mean of 5.67 g and a standard deviation 0.070 g. a vending machine will only accept coins weighing between 5.48 g and 5.82 g. what percentage of legal quarters will be rejected? round your answer to two decimal places.

Negative 5 1/12 + negative 4 1/4 + 6 3/4

For problems 29 - 31 the graph of a quadratic function y=ax^2 + bx + c is shown. tell whether the discriminant of ax^2 + bx + c = 0 is positive, negative, or zero.