How long in years, will it take for a quantity of plutonium-240 to decay to 25% of its original amount? k is the decay constant, 0.00011

Researchers were interested in whether relaxation training decreases the number of headaches a person experiences. they randomly assigned 20 participants to a control group or a relaxation training group and noted the change in number of headaches each group reported from the week before training to the week after training. which statistical analysis should be performed to answer the researchers' question?

Let event a = you roll an even number on the first cube. let event b = you roll a 6 on the second cube. are the events independent or dependent? why?

What expression is equivalent to (84+16)