In: Math
The level of pesticides found in the blubber of whales is a measure of pollution of the oceans by runoff from land and can also be used to identify different populations of whales. A sample of six male minke whales in the West Greenland area of the North Atlantic found the mean concentration of the insecticide dieldrin to be x = 356 nanograms per gram of blubber (ng/g). Suppose that the concentration in all such whales varies Normally with population standard deviation σ = 54 ng/g. Give a 95% confidence interval for estimating the mean level. (Round your answers to two decimal places.)
Solution :
Given that,
= 356
= 54
n = 6
At 95% confidence level the z is ,
= 1 - 95% =
1 - 0.95 = 0.05
/ 2 = 0.05 / 2 = 0.025
Z/2 = Z0.025 =
1.960
Margin of error = E = Z/2* (
/n)
= 1.960 * ( 54 / 6 )
= 43.21
At 95% confidence interval estimate of the population mean is,
- E <
<
+ E
356 - 43.21< < 356 + 43.21
312.79 < < 399.21
(312.79 ,399.21):