Question

In: Statistics and Probability

Hip surgery: In a sample of 120 hip surgeries of a certain type, the average surgery...

Hip surgery: In a sample of

120

hip surgeries of a certain type, the average surgery time was

136.3

minutes, with a standard deviation of

22.3

minutes.

Part: 0 / 2

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Part 1 of 2

Construct a

95%

confidence interval for the mean surgery time for this procedure. Round the answers to one decimal place. A

95%

confidence interval for the mean surgery time for this procedure is

Expert Solution

Solution:

Given:Mean,=136.3

Standard deviation, s=22.3

Sample size,n=120

Level of significance,=1-0.05=0.05

Degree of freedom,df=n=120

For df=120 and =0.05, the value to t/2=t0.05/2=0.025=1.98

Formula to find 95% confidence interval for the mean surgery time for this procedure is given by t/2*

=136.31.98*(22.3/120)

=136.34

=132.3 and 140.3

Therefore 95% confidence interval for the mean surgery time for this procedure is in between 132.3 and 140.3.

orchestra answered 2 years ago

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