Stachybotrys chartarum (atra) is the black mold that has most been associated with media reports on the toxic effects of fungal exposure. It prefers gypsum wall board as a substrate and requires very high relative humidity levels to grow. Stachybotrys chartarum is known to produce the mycotoxin, satratoxin.
When total utility is rising with the increased consumption of a good, but is rising at a decreasing rate, marginal utility is negative. b. When total utility is rising with the increased consumption of a good, and is rising at an increasing rate, marginal utility is positive. c. At the maximum point of a hill-shaped total utility curve, marginal utility is infinite. d. When total utility is falling with the increased consumption of a good, but is falling at a decreasing rate, marginal utility is positive.
If you happen to consume 10 goods, your total utility from the consumption of these 10 goods will be 160. Marginal utility is calculated by taking the difference in total utilities, and dividing by the change in quantity consumed. Most of the time the change in quantity consumed will be 1, but this is not always the case.