1. Use the data of Exercise 8 to approximate the mean, variance, and stand. deviation of the random variable X, the level of airborne cadmium dust cadmium oxide fume. Assume that these approximations are fairly accurate. Beni, what two values would you expect approximately 95% of the readings to fa_ Explain.

2. Use the data of Exercise 10 to approximate the mean, variance, and standard deviation of the random variable X, the number of gallons of liquid obtained per ton of coal feed.

3. Use the data of Exercise 11 to approximate the mean, variance, and standard deviation of the random variable X, the percentage ash content of a particular variety of peat moss.