Answer:
A. <u>Normal</u>
B. <u>30.1</u>, <u>32.9</u>
C. <u>95</u>, <u>5</u>
Step-by-step explanation:
A. The sampling distribution follows a <u>normal</u> distribution
Given that the sample size is large, we have that the sample distribution follows a normal distribution according to the central limit theorem
B. The 95% confidence interval is given as follows;
The number of residents in the study, n = 120 residents
The sample mean, = 31.5 pounds
The standard deviation, s = 7.8 pounds
The z-value for 95% confidence level, z = 1.96
Therefore, we get;
C.I. = 31.5 ± 1.96 × 7.8/√(120)
The 95% C.I. ≈ 30.1 ≤ ≤ 32.9
Therefore, we have that with 95% confidence, the population mean number of pounds per person per week is between <u>30.1</u> and <u>32.9</u>
C. Therefore, according to the central limit theorem, about <u>95</u> percent of the groups of 120 will contain the true population mean number of pounds of trash generated per person per week and about <u>5</u> percent will not contain the true population mean number of pounds of trash generated per person per week.