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| Question 464993:  In an article about the cost of health care, Money magazine reported that a visit to a hospital emergency room for something as simple as a sore throat has a mean cost of $328 (Money, January 2009). Assume that the cost for this type of hospital emergency room visit is normally distributed with a standard deviation of $92. Answer the following questions about the cost of a hospital emergency room visit for this medical service.
 What is the probability that the cost will be more than $500? (to 4 decimals)
 
 What is the probability that the cost will be less than $250? (to 4 decimals)
 
 What is the probability that the cost will be between $300 and $400? (in inches, to 4 decimals)
 
 If the cost to a patient is in the lower 8% of charges for this medical service, what was the cost of this patient’s emergency room visit? (to 2 decimals)
 $
 Answer by stanbon(75887)
      (Show Source): 
You can put this solution on YOUR website! Money magazine reported that a visit to a hospital emergency room for something as simple as a sore throat has a mean cost of $328 (Money, January 2009). Assume that the cost for this type of hospital emergency room visit is normally distributed with a standard deviation of $92. -----------------------------------------------------------
 Answer the following questions about the cost of a hospital emergency room visit for this medical service.
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 What is the probability that the cost will be more than $500? (to 4 decimals)
 z(500) = (500-328)/92 = 1.8696
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 P(x > 500) = P(z > 1.8692) = normalcdf(1.8692,100) = 0.0308
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 What is the probability that the cost will be less than $250? (to 4 decimals)
 Find the z-value of 250.
 Find the probability that z is less than that calculated z-value.
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 What is the probability that the cost will be between $300 and $400? (in inches, to 4 decimals)
 Find the z-value for 400 and for 300.
 Find the probability z is between those calculated values
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 If the cost to a patient is in the lower 8% of charges for this medical service, what was the cost of this patient’s emergency room visit? (to 2
 decimals)
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 Find the z-value with a left-tail of 8%:
 invNorm(0.08) = -1.4051
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 Solve for "x using x = zs+u
 x = -1.4051*92+328
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 x = $198.73
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 Cheers,
 Stan H.
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