Assume that trees are subjected to different levels of carbon dioxide atmosphere with 6% of the trees in a minimal growth condition at 370 parts per million (ppm), 13% at 470 ppm (slow growth), 46% at 560 ppm (moderate growth), and 35% at 630 ppm (rapid growth). what is the mean and standard deviation of the carbon dioxide atmosphere (in ppm) for these trees? the mean is enter your answer; the mean is _ ppm ppm. [round your answer to one decimal place (e. g. 98.7).] the standard deviation is enter your answer; the standard deviation is _ ppm ppm. [round your answer to two decimal places (e. g. 98.76).]