Hypothesis testing for one sample t-test.
An auditor reviewed 25 oral surgery insurance claims from a particular surgical office, determining that the mean out-of-pocket patient billing above the reimbursed amount was $275.66 with the standard deviation of $78.11.
(a) At the 5 percent level of significance, does this sample prove a violation of the guideline that the average patient should pay no more than $250 out-of-pocket? Condition your hypotheses and decision rule.
(b) Is this a close decision?
Hypotheses:
|
H0: _ = 250 vs. _ > 250
|
Level of Significance:
|
5%
|
Decision Rule
|
Reject the null hypothesis if p-value < 0.05
|
Calculation:
|
Hypothesis Test: Mean vs. Hypothesized Value
|
Hypothesized value
|
250.0000
|
Mean Sample
|
275.6600
|
std. dev.
|
78.1100
|
std. error
|
15.6220
|
n
|
25
|
df
|
24
|
t
|
1.64
|
p-value (one-tailed, upper)
|
.0568
|