Normal Distribution: 4 Problems with the z-Table | z-Scores, Heights, Bolts

Four problems on the normal distribution, from easy to hard, all solved with the z-table Φ(z) (the area under the standard normal curve to the left of z). Who did better on a test, compared with their own class (z-scores)? What percent of high-school students are shorter than 180 cm? How many of 500 students are 163 to 184 cm tall? Bolts: the percent of defective bolts, and the σ a machine needs so that at most 1% are defective, using the table in reverse. Animated on the board: no voice, just the mathematics. 0:00 Problem 1 · Who did better? 1:45 Problem 2 · Shorter than 180 cm 3:30 Problem 3 · How many students? 5:15 Problem 4 · Bolts 6:57 Answers #probability #normaldistribution #statistics #mathproblems #tutor