Regarding the normal curve, which of the following is false? 1. Many inference tests require sampling distributions that are normally distributed. 2. Theoretically, the curve reaches the axis at about z +/- 4.00, that is, the curve captures 100% of the data at these points. 3. The normal curve is a theoretical distribution of population scorres. 4. Many of the variables measured in behavioral science research have distributions that quite closely approximate the normal curve.

Features Features Normal distribution is characterized by two parameters, mean (µ) and standard deviation (σ). When graphed, the mean represents the center of the bell curve and the graph is perfectly symmetric about the center. The mean, median, and mode are all equal for a normal distribution. The standard deviation measures the data's spread from the center. The higher the standard deviation, the more the data is spread out and the flatter the bell curve looks. Variance is another commonly used measure of the spread of the distribution and is equal to the square of the standard deviation.