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.
Answer:
62
Step-by-step explanation:
The enclosing rectangle is 24 units long and 12 units high. Its area is ...
(24 units)(12 units) = 288 square units
The white circles obviously cover more than half the area, so the only viable answer choice is 62.
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If you want to go to the trouble to actually figure it out, you can find the area of each circle using the area formula ...
A = πr² = (3.14)(6²) = 113.04
Then both circles have an area of 2×113.04 = 226.08, and the shaded area is the difference between that and the rectangle area:
shaded area = 288 -226.08 = 61.92 ≈ 62
Answer:
15/4 6/5
Step-by-step explanation:
there simplified
Answer:
The factored form of x^3 -1 will be:
Step-by-step explanation:
Given the expression
Rewrite 1 as 1³
Thus, the factored form of x^3 -1 will be:
Answer:
9x^5−5x^2+7x−3
Step-by-step explanation:
2x5+3x3+−5x2+7x+1+7x5+−3x3+−4
(2x5+7x5)+(3x3+−3x3)+(−5x2)+(7x)+(1+−4)
9x^5+−5x^2+7x+−3
