A fountain on a lake sprays water in a parabolic arch modeled by the equation y = −0.4x2 + 3x, where y is the height in feet and x is the horizontal distance. A beam of light is passed through the fountain to create a rainbow effect. If the beam is directed at an angle modeled by the equation -2.2x + 4.9y = 8.18, at what distance from the ground will the beam first touch the water spray?What is the solution set of y = x2 + 2x + 7 and y = x + 7?

If x varies directly as y, and x = 7.5 when y = 10, find x when y = 4

Use the given degree of confidence and sample data to construct a confidence interval for the population mean mu . assume that the population has a normal distribution. a laboratory tested twelve chicken eggs and found that the mean amount of cholesterol was 185 milligrams with sequals 17.6 milligrams. a confidence interval of 173.8 mgless than muless than 196.2 mg is constructed for the true mean cholesterol content of all such eggs. it was assumed that the population has a normal distribution. what confidence level does this interval represent?

Which expression represent a number that is one fourth as great as 10-2a. (10-2)+4b. (10-2)÷4c. (10-2)-4d. (10-2)×4