Do children diagnosed with attention deficit/hyperactivity disorder (ADHD) have smaller brains than children without this condition? Brain scans were completed for 152 children with ADHD and 139 children of similar age without ADHD. The mean brain size for the 152 children with ADHD was 1059.4 mL with a standard deviation of 117.5 mL. The mean brain size for the 139 children without ADHD was 1104.5 mL with a standard deviation of 111.3 mL.

How could you simulate one sample under the null hypothesis?

Take 152 red cards and 139 blue cards, shuffle the cards and randomly deal them into two piles of size 152 and 139. Calculate the difference in proportion of red cards between the two samples.

Write the children's brain sizes on 291 cards, shuffle the cards and randomly deal them into two piles of size 152 and 139. Calculate the difference in mean brain size between the two samples.

Write the children's brain sizes on 291 cards, shuffle the cards and randomly deal them into two piles of size 152 and 139. Calculate the difference in standard deviation of brain size between the two samples.

Write the children's ages on 291 cards, shuffle the cards and randomly deal them into two piles of size 152 and 139. Calculate the difference in mean age between the two samples.