Aâ 9-year-old girl did a science fair experiment in which she tested professional touch therapists to see if they could sense her energy field. She flipped a coin to select either her right hand or her leftâ hand, and then she asked the therapists to identify the selected hand by placing their hand just under her hand without seeing it and without touching it. Among 283 âtrials, the touch therapists were correct 124 times. Use a 0.10 significance level to test the claim that touch therapists use a method equivalent to random guesses. Do the results suggest that touch therapists areâ effective?

Given that a 9 year-old girl did a science fair experiment in which she tested professional touch therapists to see if they could sense her energy field. She flipped a coin to select either her right hand or her leftâ hand, and then she asked the therapists to identify the selected hand by placing their hand just under her hand without seeing it and without touching it.

Correct were 124 and total 283

Hence proportion = [tex]\frac{124}{283} =0.4382[/tex]

If simple guessing is done p =0.5

[tex]H_0: p =0.5\\H_a: p >0.5[/tex]

(One tailed at 0.1)

p diff = 0.0618

std error = [tex]\sqrt{pq/n} =0.0297[/tex]

Test statistic z= p diff/se =2.08

p value =0.0188

Since p<0.10, we reject H0

The results suggest that touch therapists areâ effective