Total of 581 students. if the ratio of girls to boys in the class is 3: 4, how many more boys than girls are in the class

Nnnnneeedd 1.find the residual if you know the actual number is 5.2 and the predicted value is 4.8

Astuntman jumping off a 20-m-high building is modeled by the equation h=20-5t^2, where t is the same in seconds. a high-speed camera is ready to film him between 15m and 10m above the ground. for which interval of time should the camera film him?

Events a and b are independent. the probability of a occurring is 2/5. the probability of b occurring is 1/4. what is p(a and b)?