In: Statistics and Probability
A simple random sample of epicenter depths of 51 earthquakes has a mean of 9.808 kilometers (km) and a standard deviation of 5.013 km. Determine the critical value of t and the margin of error, and then construct the 95% confidence interval estimate of the mean epicenter depth of all earthquakes.
Given that
n = 51, x̅ = 9.808 km S.D = S = 5.013 km
d.f = n – 1 = 50
α = 1-95% = 1-0.96 = 0.05
tα/2 d.f = 2.01
Margin of error = critical value × s/√n
= 2.01 × 5.013/√51
M.E = 1.4099
∴ 95% confidence interval for population mean is
[x̅ ± M.E] = [9.808 ± 1.4099]
[8.3981, 11.2179]
∴95% confidence interval estimate of the mean epicenter depth of all earthquake lies between 8.3981 and 11.2179.
∴95% confidence interval estimate of the mean epicenter depth of all earthquake lies between 8.3981 and 11.2179.