To compare the average amount of time that canadians and americans spend commuting, a researcher collects a sample of canadians and americans. The canadians spend an average of hours a week commuting, with a standard deviation hours. The mean and standard deviation for the sample of americans is hours and hours, respectively. The standard error of the difference of sample means is:.

Jim has found that he must consume 2,300 calories a day to reach his health goals, but he doesn't want to give up his afternoon snack of pretzels. unfortunately, he tends to eat the entire bag — which amounts to 1,300 calories! what strategy should jim use to improve his habits?

The graph shows the populations of two species in a particular region over two decades. based on the graph, what can you conclude about the relationship between the two species? a. the two species have a parasitic relationship. b. the two species are mutualistic in nature. c. the two species exhibit commensalism. d. the two species have a prey-predator relationship. e. the two species have a familial relationship.

Rick is on a bicycle trip. every 4 days he bikes 230 km. if rick keeps this same pace for 16 days, how many kilometers will he bike?