Answer:
The confidence interval for the population variance of the thicknesses of all aluminum sheets in this factory is Lower limit = 2.30, Upper limit = 4.83.
Step-by-step explanation:
The confidence interval for population variance is given as below:
![[(n - 1)\times S^{2} / X^{2} \alpha/2, n-1 ] < \alpha < [(n- 1)\times S^{2} / X^{2} 1- \alpha/2, n- 1 ]](https://tex.z-dn.net/?f=%5B%28n%20-%201%29%5Ctimes%20S%5E%7B2%7D%20%20%2F%20%20X%5E%7B2%7D%20%20%5Calpha%2F2%2C%20n-1%20%5D%20%3C%20%5Calpha%20%3C%20%5B%28n-%201%29%5Ctimes%20S%5E%7B2%7D%20%20%2F%20X%5E%7B2%7D%201-%20%5Calpha%2F2%2C%20n-%201%20%5D)
We are given
Confidence level = 98%
Sample size = n = 81
Degrees of freedom = n – 1 = 80
Sample Variance = S^2 = 3.23
![X^{2}_{[\alpha/2, n - 1]} = 112.3288\\\X^{2} _{1 -\alpha/2,n- 1} = 53.5401](https://tex.z-dn.net/?f=X%5E%7B2%7D_%7B%5B%5Calpha%2F2%2C%20n%20-%201%5D%7D%20%20%20%3D%20112.3288%5C%5C%5CX%5E%7B2%7D%20_%7B1%20-%5Calpha%2F2%2Cn-%201%7D%20%3D%2053.5401)
(By using chi-square table)
[(n – 1)*S^2 / X^2 α/2, n– 1 ] < σ^2 < [(n – 1)*S^2 / X^2 1 -α/2, n– 1 ]
[(81 – 1)* 3.23 / 112.3288] < σ^2 < [(81 – 1)* 3.23/ 53.5401]
2.3004 < σ^2 < 4.8263
Lower limit = 2.30
Upper limit = 4.83.
<em><u>Question:</u></em>
Hector has a floor plan showing his new house. On the floor plan, his bedroom is 3 inches wide and 3 1/2 inches long. The scale of the floor plan is 1/4 inch = 1 foot. What is the actual length of Hector’s room?
<em><u>Answer:</u></em>
The actual length of Hector room is 14 foot
<em><u>Solution:</u></em>
Given that, On the floor plan, his bedroom is 3 inches wide and 
inches long
<em><u>The scale of floor plan is given as:</u></em>
Therefore,
To find: Actual length of floor
From given question,
Converting the mixed fraction to improper fraction,
Since, 1 inch = 4 foot
Thus actual length of Hector room is 14 foot
Answer:
Slope EQUALS: 
Step-by-step explanation:
y=-x+3
9514 1404 393
Answer:
(b) 9
Step-by-step explanation:
The product of segment lengths to the near and far intersection with the circle is the same for both secants.
4(4+5) = 3(3+x) . . . . the above statement with numbers filled in
36 = 9 +3x . . . . . . . simplify
12 = 3 +x . . . . . . . . divide by 3
9 = x . . . . . . . . . . . subtract 3
