Posted: December 23rd, 2016

Before conducting a maze learning experiment you weigh two groups of rats

Before conducting a maze learning experiment you weigh two groups of rats. The experimental group, which contains 20 rats, has an average weight of 18 ounces, while the control group, which contains 10 rats, has an average weight of 15 ounces. What would be the average weight of the two groups?
1. 16
2. 16.5
3. 17
4. 18