Question 211120:  A researcher predicts that listening to music while solving math problems will 
make a particular brain area more active. To test this, a research participant has 
her brain scanned while listening to music and solving math problems, and the 
brain area of interest has a percent signal change of 58. From many previous 
studies with this same math-problems procedure (but not listening to music), it 
is known that the signal change in this brain area is normally distributed with a 
mean of 35 and a standard deviation of 10. Using the .01 level, what should the 
researcher conclude? Solve this problem explicitly using all five steps of 
hypothesis testing, and illustrate your answer with a sketch showing the comparison 
distribution, the cutoff (or cutoffs), and the score of the sample on this 
distribution. Then explain your answer to someone who has never had a course 
in statistics (but who is familiar with mean, standard deviation, and Z score 
 Answer by stanbon(75887)      (Show Source): 
You can  put this solution on YOUR website! problems will make a particular brain area more active.  
To test this, a research participant has her brain scanned while listening to music and solving math problems, and the brain area of interest has a percent signal change of 58.  
From many previous studies with this same math-problems procedure (but not listening to music), it is known that the signal change in this brain area is normally distributed with a mean of 35 and a standard deviation of 10.  
Using the .01 level, what should the researcher conclude? 
-------------------------- 
Ho: u = 35 
Ha: u > 35 
----------------- 
Critical Value: z = 2.326 
Test statistic: z = (35-58)/10 = 2.3 
p-value = P(z>2.3) = 0.0107 
--------------------------------- 
Since the p-value is greater than 1%, do not reject Ho 
But the decision is very close. More testing should be done. 
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Cheers, 
Stan H.  
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