Question 1161598:  The average per capita spending on health care in the United States 
is $5274. If the standard deviation is $600 and the 
distribution of health care spending is approximately 
normal, what is the probability that a randomly 
selected person spends more than $6000? Find the 
limits of the middle 50% of individual health care 
expenditures. 
 Answer by Boreal(15235)      (Show Source): 
You can  put this solution on YOUR website! z=(x-mean).sd or (6000-5274)/600=1.21 
probability z>1.21 is 0.1131 
middle 50% occurs when z=-0.6745 to z=+0.6745 (25th and 75th percentiles 
z*sd=+/- 404.69.  Add to and subtract that from the mean to get the limits 
($4869.31, $5678.69)
 
Check on a TI-83 by 2ndVARS 2 ENTER(4869.31,5678.69,5274,600) ENTER That gives you the probability of that interval. 
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