Using a standard normal distribution table or calculator, we can find the z-score corresponding to an IQ score of 117:
z = (117 - 100) / 15 = 1.13
Looking at the standard normal distribution table, we can find that the area to the left of z = 1.13 is 0.8708. This means that approximately 87.08% of people have an IQ score less than 117. Rounded to the nearest tenth, this is 87.1%. Therefore, about 87.1% of people have an IQ score less than 117.