Answer:
Kindly check explanation
Step-by-step explanation:
Given the following :
Assume a normal distribution :
Mean (m) = 328
Standard deviation (sd) = 92
To obtain Zscore :
Zscore = (x - m) / sd
What is the probability that the cost will be more than $500?
x = $500
Zscore = (500 - 328) / 92 = 172 / 92 = 1.869 = 1.87
1 - p(Z < 1.87) = 1 - 0.9693 = 0.0307
b. What is the probability that the cost will be less than $250?
x = $250
Zscore = (250 - 328) / 92 = - 78 / 92 = - 0.8478 = - 0.85
p(Z < - 0.85) = 0.1977
c. What is the probability that the cost will be between $300 and $400?
x = 300
Zscore = (300 - 328) / 92 = - 28/ 92 = -0.30
p(Z < - 0.3) = 0.3821
x = 400
Zscore = (400 - 328) / 92 = 72/ 92 = 0.783
p(Z < 0.783) = 0.7823
0.7823 - 0.3821 = 0.4002
d. 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?
Probability is lower 8%
P (Z < Zscore) = 0.08
Zscore of 0.08 corresponds to - 1.41 on the z table
Zscore = (x - m) / sd
-1.41 = (x - 328) / 92
-129.72 = x - 328
-129.72 + 328 = x
x = 198.28