A medical researcher needs nine people to test the effectiveness of an experimental drug. If 10 people have volunteer for test and how many ways can nine people be selected?

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.

How do businesses a country's economy? a. by investing in goods and services b. by increasing the unemployment rate c. by making profits

Which statement describes surface features called maria on the moon