Answer:
<em>The area of Marlien's living room is 420 square ft</em>
Step-by-step explanation:
Before calculating the real dimensions of Marlien's living room, we must find the value of x.
Given the total shape of the house is a rectangle, then both widths must be equal and both lengths must be equal.
The widths are already written width identical expressions x-2+x, but the lengths are given as different functions of x. Equating both expressions, we have:
Simplifying:
-10 + x - 2 = 2
x = 10 + 2 + 2
x = 14
Since x=14 feet, the dimensions of Marlien's living room are
width=x=14 feet
length=2x+2=30 feet
Thus the area is:
A = 14*30 = 420 square ft
The area of Marlien's living room is 420 square ft
Answer:
<em>Correct answer:</em>
<em>A. I and II</em>
<em></em>
Step-by-step explanation:
First of all, let us have a look at the steps of finding inverse of a function.
1. Replace y with x and x with y.
2. Solve for y.
3. Replace y with 
Given that:
Now, let us find inverse of each option one by one.
I. y = x, a(x) = x
Replacing y with and x with y:
x = y
x = 
= 
Hence, I is true.
II. 
Replacing y with and x with y:
= Hence, II is true.
III. 
Replacing y with and x with y:
Hence, III is not true.
IV. 
Replacing y with and x with y:
![x =y^{3}\\\Rightarrow y = \sqrt[3] x\\\Rightarrow a^{-1}(x) = \sqrt[3]{x} \ne a(x)](https://tex.z-dn.net/?f=x%20%3Dy%5E%7B3%7D%5C%5C%5CRightarrow%20y%20%3D%20%5Csqrt%5B3%5D%20x%5C%5C%5CRightarrow%20a%5E%7B-1%7D%28x%29%20%3D%20%5Csqrt%5B3%5D%7Bx%7D%20%5Cne%20a%28x%29)
Hence, IV is not true.
<em>Correct answer:</em>
<em>A. I and II</em>
<em></em>
We have a sample of 28 data points. The sample mean is 30.0 and the sample standard deviation is 2.40. The confidence level required is 98%. Then, we calculate α by:
The confidence interval for the population mean, given the sample mean μ and the sample standard deviation σ, can be calculated as:
![CI(\mu)=\lbrack x-Z_{1-\frac{\alpha}{2}}\cdot\frac{\sigma}{\sqrt[]{n}},x+Z_{1-\frac{\alpha}{2}}\cdot\frac{\sigma}{\sqrt[]{n}}\rbrack](https://tex.z-dn.net/?f=CI%28%5Cmu%29%3D%5Clbrack%20x-Z_%7B1-%5Cfrac%7B%5Calpha%7D%7B2%7D%7D%5Ccdot%5Cfrac%7B%5Csigma%7D%7B%5Csqrt%5B%5D%7Bn%7D%7D%2Cx%2BZ_%7B1-%5Cfrac%7B%5Calpha%7D%7B2%7D%7D%5Ccdot%5Cfrac%7B%5Csigma%7D%7B%5Csqrt%5B%5D%7Bn%7D%7D%5Crbrack)
Where n is the sample size, and Z is the z-score for 1 - α/2. Using the known values:
![CI(\mu)=\lbrack30.0-Z_{0.99}\cdot\frac{2.40}{\sqrt[]{28}},30.0+Z_{0.99}\cdot\frac{2.40}{\sqrt[]{28}}\rbrack](https://tex.z-dn.net/?f=CI%28%5Cmu%29%3D%5Clbrack30.0-Z_%7B0.99%7D%5Ccdot%5Cfrac%7B2.40%7D%7B%5Csqrt%5B%5D%7B28%7D%7D%2C30.0%2BZ_%7B0.99%7D%5Ccdot%5Cfrac%7B2.40%7D%7B%5Csqrt%5B%5D%7B28%7D%7D%5Crbrack)
Where (from tables):
Finally, the interval at 98% confidence level is:
1. Slope = -7
Y intercept= 8
