STAT101 Study Guide - Standard Deviation, Normal Distribution
Document Summary
Randy typically does well in math classes- his average grade is 89 with a standard deviation of: his grades follow a normal distribution. What percent of the time does randy earn between an 89 and a 92 in a math class, Find the percentage of the time when his grade is between 89 and 92: describe the student"s grade pattern. This curve describes the student"s grade pattern (normal distribution, mean = 89, sd = 3: show the portion of grades being asked. The shaded area under the curve is between grades 89 and 92: calculate how far the two grades are from the standard deviation (also called z-score z). The formula for z-score is: z = (x - ) / . Plugging the given values into the formula above, we get: Z-score for 89: z = (89 - 89) / 3 = 0.
