Fluorine-18 has a half life of 118 minutes. If a sample starts at 250g, how much remains after 472 minutes

An automated water dispenser fills packets with one liter of water on average, with a standard deviation of 5 milliliter. the manual says that after a year of operation the dispenser should be tested to see if it needs recalibration. a year later a number of filled packets are set aside and measured separately. it is found that the average packet now contains about 0.995 liters. does the dispenser need calibration? explain your answer.

What is the frequency of the sinusoidal graph?

Ab and bc form a right angle at point b. if a= (-3,-1) and b= (4,4) what is the equation of bc?