Respuesta :
Answer:
The 80% confidence interval for the mean consumption of meat among people over age 23 is between 4 and 4.2 pounds.
Step-by-step explanation:
We have that to find our [tex]\alpha[/tex] level, that is the subtraction of 1 by the confidence interval divided by 2. So:
[tex]\alpha = \frac{1-0.8}{2} = 0.1[/tex]
Now, we have to find z in the Ztable as such z has a pvalue of [tex]1-\alpha[/tex].
So it is z with a pvalue of [tex]1-0.1 = 0.9[/tex], so [tex]z = 1.28[/tex]
Now, find M as such
[tex]M = z*\frac{\sigma}{\sqrt{n}}[/tex]
In which [tex]\sigma[/tex] is the standard deviation of the population and n is the size of the sample.
[tex]M = 1.28*\frac{0.7}{\sqrt{164}} = 0.07[/tex]
The lower end of the interval is the mean subtracted by M. So it is 4.1 - 0.07 = 4.03 pounds
The upper end of the interval is the mean added to M. So it is 4.1 + 0.07 = 4.17 pounds
Rounded to one decimal place
The 80% confidence interval for the mean consumption of meat among people over age 23 is between 4 and 4.2 pounds.
