Question

A research study was conducted to determine if children with attention deficit/hyperactivity disorder, ADHD, have smaller brains than children without the condition. She computed a z score of -1.73. Using a left tailed test of hypothesis, find the p-value, and at a 5% confidence level, determine if the data provids evidence that children with ADHD have smaller brains than the children without the condition.

Answer 1

Solution,

This is left tailed test,

Test statistic = z = -1.73

P(z < -1.73)

P-value = 0.0418

$\alpha$ = 0.05  

P-value < $\alpha$

Reject the null hypothesis .

There is sufficient evidence to suggest that  children with ADHD have smaller brains than the children without the condition