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.
okay so you would go down to -8, then the slope would be 4/1 which means to go up four and then over one. then you have the line.
i hope this helps you!
Answer:
She used a 20, 10, 5, and 1, she also used a quarter, nickel, and 2 pennies
Step-by-step explanation:
The length and width of the rug is 20 and 11 feet respectively
The given parameters;
dimension of the room = 19 ft by 28 ft
maximum area of rug she can afford = 220 ft²
For a uniform stripe of floor around the rug, then suppose the uniform excess length of the floor to removed from each dimension = y
(28-2x)(19-2x)=220
532-94x+4x^2=220
4x^2-94x+312=0
x=39/2,4
For x=39/2, dimensions are negative.
The uniform dimension of the floor to be covered by the maximum area of rug she can afford = (28 - 4×2) and (19 -2×4 ) = 20 and 11
Thus, the dimensions of the rug should be 20 feet and 11 feet
- The area of a rectangle is length times breadth.
- Area is the total squares cm occupied by a closed figure.
To learn more about area of a rectangle visit:
brainly.com/question/20693059
#SPJ9
