How do you get the mid year average?

What is the probability a girl is chosen if 15 students are girls and 10 students are boys? What conclusions you can you draw about the society of Jericho from looking at this illustration of the city? How effective is plan b if taken 15 hours after intercourse when the girl finished her period only 2 days before intercourse? In a race with 8 runners what is the probability of predicting the first second and third place finishers? Are you more likely to get pregnant or get an STD? Where can one purchase a rolling tote bag? What is the difference between a variable being tested and a variable being controlled? How many skateboards are sold in US per year? What risk factor is most likely to be encountered in the workplace? What is probability that two heterozygous parents would have an offspring that produced round seeds? In critical thinking what does bias mean? What is non-directional research hypothesis? What is the probability of rolling an even number with 3 dice? Is the Z-test the same as Z-scores? What does two to the third power equal? What do you mean by degree of relation in relational data base management system? What do you call the difference between the highest and lowest number in a data set? How much sex could a man sex? What are the disadvantages of data redundancy? What shape with 5 faces and 5 corners?