Question

Noise levels at 3 volcanoes were measured in decibels yielding the following data:

142,113,135

Construct the 90%90% confidence interval for the mean noise level at such locations. Assume the population is approximately normal.

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Step 2 of 4:

Calculate the sample standard deviation for the given sample data. Round your answer to one decimal place

Answer 1

Solution:- Given that values 142,113,135 90% confidence interval

X = 130, s = 15.1327, n = 3, df = n-1 = 2, t = 2.920

90% confidence interval for the mean = X +/- t*s/sqrt(n)

= 130 +/- 2.920*15.1327/sqrt(3)

= 104.4883 , 155.5117

Step : 2 sample standard deviation : 15.1327