Which of the following are characteristics of a normal distribution? The area under the part of a normal curve that lies within standard deviations of the mean is approximately . The mean, median, and mode are located at the center of the distribution. The normal curve is a discrete distribution. The normal distribution curve is unimodal. The area under the part of a normal curve that lies within standard deviations of the mean is approximately . The area under the part of a normal curve that lies within standard deviation of the mean is approximately . The normal distribution curve is symmetric about the standard deviation. The total area under the normal distribution curve is . The normal distribution curve crosses the axis. A normal distribution curve is bell shaped.