The best research method to investigate cause and effect relationships between variables is

Which of the following is NOT a characteristic of a normal distribution?

a. Most scores fall near the mean b. The normal distribution forms a bell curve when graphed c. The curve is symbolic, meaning that the tail touches the y-axis at plus 3 standard deviation d. The mean, median, and mode all fall at the center of the distribution

After her car accident, Mollie had no memory of the party she'd been to in the hours before she suffered a head injury. She has no difficulties, however, encoding and storing new information. Mollie is suffering from __________ amnesia

a. anterograde b. retroactive c. retrograde d. proactive