Question

A. Explain normal distribution. B. In your own words, how do you use the normal distribution table (Appendix B)?

Answer 1

a)Explain normal distribution: A bell-shaped curve, describing the spread of a characteristic throughout a population. It is also known as the Gaussian distribution, is a probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean. Two Pieces of data that specify a Distribution: Mean (u) and Standard Deviation (0)

b) Appendix table gives the area under the standardized normal curve from 0 to z For example: If z is the standard normal random variable, then Prob (0 sz< 1.32) = 0.4066 Prob (z 2 1.32) = 0.5000 -0.4066 = 0.0934 • Area from a value (Use to compute p from Z) Value from an area (Use to compute Z for confidence intervals) Specify Parameters: Meano SD 1 • Above 1.32 Below 1.96 Between - 1.96 Outside -1.96 and 1.96 and 1.96 Results: Area (probability) 0.0934