Answer:
I. 94.99 in²
II. $0.23
Step-by-step explanation:
<u>Given the following data;</u>
Diameter of wheel = 11 inches
Cost of wheel = $21.35
<em><u>Part A</u></em>
To find the area;
We know that a wheel is circular in nature. Thus, the area of a circle is given by the formula;
Substituting into the equation, we have;
<em>Area, A = 94.99 in²</em>
<em><u>Part B</u></em>
To find cost per square inch;
<u>Cost per square inch = $0.23</u>
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.