Experts agree that early diagnosis of autism spectrum disorders (ASD) is important so children get the support they need to develop, progress, and thrive. The National Center for Biotechnology Information conducted a study in which the ages at diagnosis for a random sample of 421 children with ASD were recorded. The average age was 38.2 months with a standard deviation of 8.7 months. Estimate the mean age at diagnosis for children with ASD with 96% confidence.