There are approximately one billion smartphone users in the world today. In the United States the ages 13 to 55 of smartphone users approximately follow a normal distribution with approximate mean and standard deviation of 39 years and 12.5 years, respectively. Determine the probability that a random smartphone user in the age range 13 to 55 is between 23 and 64.7 years old. Round your answer to four decimal digits. Below is a sketch of the normal curve showing the area to be determined