Suppose a sample of 60 cars is taken what is the probability that the sample average speed is less than 131.5

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?

17 a tourist was planning a trip by car for travelling at some constant speed for 2.5 hours. however, he found that if he increases the speed by 20 km/h he can cover the same distance in 30 minutes less time than it was planned. what was the planned speed of the tourist, in km/h?

Jerrold has to buy 12 copies of a textbook which costs $36.25 per copy. how much must he spend for them?