A certain candle is designed to last nine hours. However, depending on the wind, air bubbles in the wax, the quality of the wax, and the number of times the candle is re-lit, the actual burning time (in hours) is a uniform random variable with a = 5.5 and b = 9.5.
Suppose one of these candles is randomly selected.
(a) Find the probability that the candle burns at least six hours.
(b) Find the probability that the candle burns at most seven hours.
(c) Find the mean burning time. Find the probability that the burning time of a randomly selected candle will be within one standard deviation of the mean. (Round your answer to four decimal places.)
(d) Find a time t such that 25% of all candles burn longer than t hours.

Part a what is the area of triangle i? show your calculation. part b triangles i and ii are congruent (of the same size and shape). what is the total area of triangles i and ii? show your calculation. part c what is the area of rectangle i? show your calculation. part d what is the area of rectangle ii? show your calculation. part e rectangles i and iii have the same size and shape. what is the total area of rectangles i and iii? show your calculation. part f what is the total area of all the rectangles? show your calculation. part g what areas do you need to know to find the surface area of the prism? part h what is the surface area of the prism? show your calculation. part i read this statement: “if you multiply the area of one rectangle in the figure by 3, you’ll get the total area of the rectangles.” is this statement true or false? why? part j read this statement: “if you multiply the area of one triangle in the figure by 2, you’ll get the total area of the triangles.” is this statement true or false? why?