The figure shows a normal distribution with mean m and standard deviation d, including approximate percents of the distribution in each of the six regions shown.
For a population of 800,000 subway riders, the numbers of subway trips taken per rider last January are approximately normally distributed with a mean of 56 trips and a standard deviation of 13 trips. Approximately how many of the riders took between 30 and 43 trips last January?60,000, 110,000, 160,000, 210,000, 270,000
1 Explanation