Autistic children often have a small head circumference at birth, followed by a sudden and excessive increase in head circumference during the first year of life. A recent study¹examined the brain tissue in autopsies of seven autistic male children between the ages of 2and 16. The mean number of neurons in the prefrontal cortex in non-autistic male children of the same age is about 1.15billion. The prefrontal cortex is the part of the brain most disrupted in autism, as it deals with language and social communication. In the sample of seven autistic children, the mean number of neurons in the prefrontal cortex was 1.94billion with a standard deviation of 0.50billion. The values in the sample are not heavily skewed. Use the-distribution to test whether this sample provides evidence that autisticmale children have more neurons (on average) in the prefrontal cortex than non-autistic children. (This study indicates that the causes of autism may be present before birth.)

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conclusion, reject or do not reject null hypothesis?

Does the sample provide evidence that autistic male children have more neurons (on average) in the prefrontal cortex than non-autistic children?