In a random sample of 60 students in first grade, the mean hours of sleep per night was 9.6 with a standard deviation of 0.51. In a random sample of 40 students in 12th grade, the mean hours of sleep per night was 7.2 with a standard deviation of 0.62. Which interval is a 99% confidence interval for the difference between the mean hours of sleep?

Which expression is equivalent to sq-80

Using graph paper, determine the line described by the given point and slope. click to show the correct graph below.(0, 0) and 2/3

Brittany has designed four different birdcages, each with the same volume: a square pyramid, a cylinder, a cone, and a sphere. the zoo wants to use one of brittany’s designs but plans to change the volume of the cage. find the design change that would result in the birdcage with the greatest volume. a.) increase the area of the base of the square pyramid by a factor of ten. b.) increase the height of the cylinder by a factor of ten. c.) increase the radius of the cone by a factor of ten. d.) increase the radius of a sphere by a factor of ten.