It is estimated that in the general population about 9 out of every 1000, or 0.009, children are diagnosed with autism. A recent study included 92 six-month-old babies who had a sibling with autism. Twenty-eight of these babies were later diagnosed with autism. Use StatKey or other technology to find a 99% confidence interval for the proportion of siblings of autistic children likely to have autism. (In the study, brain scans taken at six-months old predicted almost perfectly which children would later be diagnosed with autism, providing the earliest known method for diagnosing the disease.)