The mayor is interested in finding a 98% confidence interval for the mean number of pounds of trash per person per week that is generated in the city. The study included 129 residents whose mean number of pounds of trash generated per person per week was 34.2 pounds and the standard deviation was 8.2 pounds. a. The sampling distribution follows a distribution.
b. With 95% confidence the population mean number of pounds per person per week is between and pounds.
c. If many groups of 120 randomly selected people in the city are studied, then a different confidence interval would be produced from each group. About percent of these confidence intervals will contain the true population mean number of pounds of trash generated per person per week and about percent will not contain the true population mean number of pounds of trash generated per person per week.

Solution :

Given :

Sample mean,

Sample size, n = 129

Sample standard deviation, s = 8.2

a. Since the population standard deviation is unknown, therefore, we use the t-distribution.

b. Now for 95% confidence level,

   α = 0.05, α/2 = 0.025

  From the t tables, T.INV.2T(α, degree of freedom), we find the t value as

  t =T.INV.2T(0.05, 128) = 2.34

  Taking the positive value of t, we get  

  Confidence interval is ,

 (32.52, 35.8)

 95% confidence interval is  (32.52, 35.8)

So with confidence of the population of the mean number of the pounds per person per week is between 32.52 pounds and 35.8 pounds.

c. About of confidence intervals which contains the true population of mean number of the pounds of the trash that is generated per person per week and about that doe not contain the true population of mean number of the pounds of trashes generated by per person per week.  

pay attention in your classes and concentrate the best thing you can do to raise your test scores is to pay attention when you're supposed to be learning the material: in class!

take good notes.

do your homework.

use mnemonics and other tricks.

do practice tests.

note: the best i know.

hi how are you doing today? if you ever need just tell me

step-by-step explanation: