A test statistic is a mathematical formula used to determine how far a sample outcome deviates or varies from the outcome that is assumed to be true in the null hypothesis.

The cerebral cortex of humans is so large it should not fit in our skull. The only reason it does is because of its _____

a) shrinkage during gestation. b) convolutions. c) extension into the spinal cord. d) absence of fluid.

Caffeine will interfere with ________

a. the digestion of foods and liquids b. normal cardiovascular functioning when resting c. prescribed medications like tranquilizers and sedatives d. processing of information by the cerebral cortex