I am trying to learn Normal Distribution in relation to Statistics. The example given is: Predict the distribution of IQ scores of 1000 people if we assume that IQ scores are normally distributed, with a mean of 100 and a standard deviation of 15. I understand how they got the breaking point around the mean. What I do not understand is how they got the percentages that they did. Here is their layout.
Scores Percent Expected number
55 to 70 2.3% 23
Above 70 to 85 13.6% 136
Above 85 to 100 34.1% 341
Above 100 to 115 34.1% 341
Above 115 to 130 13.6% 136
Above 130 to 145 2.2% 22
Above 145 .1% 1

How did they get those percentages?