a. Find the mean and standard deviation of the sanitation scores. x = 89.15 (Round to two decimal places as needed.) S = 4.34 (Round to two decimal places as needed.) b. Calculate the intervals x ±s, X±2s, x ±3s. x+s= (84.81,93.49 (Round to two decimal places as needed.) x+2s = ( 80.47, 97.83) (Round to two decimal places as needed.) x±3s = ( 76.13, 102.17) (Round to two decimal places as needed.) c. Find the percentage of measurements in the data set that fall within each of the intervals in part b. The percentage of the measurements that fall within the interval X ±s is %.

Find the mean hourly cost when the cell phone described above is used for 240 minutes.

Planetary Velocity The following table gives the mean velocity of planets in their orbits versus their mean distance from the sun. Note that 1AU astronomical unit is the mean distance from Earth to the sun, abut 93 million miles. Planet d=distance AU v=velocity km/sec Mercury 0.39 47.4 Venus 0.72 35.0 Earth 1.00 29.8 Mars 1.52 24.1 Jupiter 5.20 13.1 Saturn 9.58 9.7 Uranus 19.20 6.8 Neptune 30.05 5.4 Astronomers tell us that it is reasonable to model these data with a power function. a Use power regression to express velocity as a power function of distance from the sun. b Plot the data along with the regression equation. c An asteroid orbits at a mean distance of 3AU from the sun. According to the power model you found in part a, what is the mean orbital velocity of the asteroid?