NEED ASAP PLS 20 points! Need all answers filled out

In a class, there are 12 girls. if the ratio of boys to girls is 5: 4 how many boys are there in the class

Bob is putting books on a shelf and takes a break after filling 18 1/2 inches on the book shelf. the book shelf is now 2/3 full. how long is the entire bookshelf?

The human resources manager at a company records the length, in hours, of one shift at work, x. he creates the probability distribution below. what is the probability that a worker chosen at random works at least 8 hours? probability distribution px(x) 6 hours 7 hours 8 hours 9 hours 10 hours 0.62 0.78 пол