Problem 3 (6 pts) An EWMA chart with L = 2.8 is used to monitor individual observations measured in a process. The process mean and standard deviation are 50 and 2, respectively. If Z3 47, Z4 48.6, X4 = 55 calculate: (a) Smoothing coefficient λ. (b) Control limits for Z4. (c) Steady-state control limits.

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?