Answer: ....
Step-by-step explanation:
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:
80.8
Step-by-step explanation: 0.7x4x6=16.8
16.8+8 to the 2nd power= 80.8
Answer:
The value of first coin will be $151.51 more than second coin in 15 years.
Step-by-step explanation:
You have just purchased two coins at a price of $670 each.
You believe that first coin's value will increase at a rate of 7.1% and second coin's value 6.5% per year.
We have to calculate the first coin's value after 15 years by using the formula

Where A = Future value
P = Present value
r = rate of interest
n = time in years
Now we put the values



A = (670)(2.797964)
A = 1874.635622 ≈ $1874.64
Now we will calculate the value of second coin.



A = 670 × 2.571841
A = $1723.13
The difference of the value after 15 years = 1874.64 - 1723.13 = $151.51
The value of first coin will be $151.51 more than second coin in 15 years.
Option B
5 hundredths is not the way to express 0.50
<h3><u>Solution:</u></h3>
Given that Three of the choices are ways to express 0.50
To find: wrong option
Let us first write 0.50 in different ways
<h3><em><u>
To convert a Decimal to a Fraction follow these steps:
</u></em></h3>
Step 1: Write down the decimal divided by 1, like this: decimal 1.
Step 2: Multiply both top and bottom by 10 for every number after the decimal point. ...
Step 3: Simplify (or reduce) the fraction.

means 50 hundredths
<h3>Therefore option D is correct</h3>
On simplifying
we can write,

means one half
<h3>Therefore option A (one half) is correct</h3>
Similarly, \frac{5}{10} means 5 tenths
<h3>Therefore Option C is also correct</h3>
Thus the wrong option is B
<em><u>Justification:</u></em>
5 hundredths can be written as:

Therefore option B is wrong