A study finds that the number of gallons of water used each month per household in a residential neighborhood are normally distributed with a mean of 470 gallons and a
standard deviation of 50 gallons. A household is randomly selected. What is the
probability that the household uses 480 gallons of water or less per month?

Astudent is determining the influence of different types of food on the growth rate of spiders. she feeds one group of spiders two caterpillars twice a week. the other group received similarly-sized beetles twice a week. she records the amount of time required for individuals to reach sexual maturity. her hypothesis is that the spiders feeding on caterpillars will have a faster growth rate because caterpillars have a higher protein content compared to beetles. in this experiment, what is the dependent variable? spiders assigned to different feeding groups. time required to reach sexual maturity number of prey items fed twice a week. growth rates of each group.