6.70 Another contributor to air pollution is sulfur dioxide.

Shown below are 12 peak sulfurdioxide measurements (in ppm) for 1990 from randomly selected U.S. sites:

0.003, 0.001, 0.014, 0.024, 0.024, 0.032, 0.038, 0.042, 0.043, 0.044, 0.047, 0.061 a Should the normal distribution be used as a model for these measurements?

b From a Q–Q plot for these data, approximate the mean and standard deviation. Check the approximation by direct calculation.