Amultiple choice test consists of eight questions, each of which has five choices. each question has exactly one correct answer. william guesses randomly at each answer. what is the probability that he gets six or fewer questions correct?

William has clearly not studied. 

There are five choices for eight questions. The probability of getting a question right is 1 in 5 or 20%. The probability of getting all of them right is 0.00000256. The probability of him 6 or fewer questions correct is over 99% likely. 

Ithink if im not mistaking b is -3 but im not a 100% sude

The major difference is that a histogram is only used to plot the frequency of score occurrences in a continuous data set that has been divided into classes, called bins.  bar charts, on the other hand, can be used for a great deal of other types ofvariables  including  ordinal  andnominal  data sets.