Question

Noise levels at 5 volcanoes were measured in decibels yielding the following data:

108,133,140,129,136

Construct the 98% confidence interval for the mean noise level at such locations. Assume the population is approximately normal.

Step 3 of 4: Find the critical value that should be used in constructing the confidence interval. Round your answer to three decimal places.

Step 4 of 4: Construct the 98% confidence interval. Round your answer to one decimal place.

Answer 1

Solution :

From the given data ,

n = 5

s = 12.5

= 646 / 5 = 129.2

t _/2,df = 3.747

Margin of error = E = t_/2,df * (s /n)

= 3.747 * (12.5 / 5)

Margin of error = E = 20.9

The 98% confidence interval estimate of the population mean is,

- E < < + E

129.2 - 20.9 < < 129.2 + 20.9

108.3 < < 150.1

(108.3 , 150.1)