Answer:
15
Step-by-step explanation:
Given: y is directly proportional to
when x = 7, y = 9
To find: y when x = 23
Solution:
u and v are said to be proportional if
where k is a constant of proportionality.
As y is directly proportional to
when x = 7, y = 9,
![y=k\sqrt{x+2}\\](https://tex.z-dn.net/?f=y%3Dk%5Csqrt%7Bx%2B2%7D%5C%5C)
Put x = 7, y = 9
![9=k\sqrt{7+2}=3k\\ k=\frac{9}{3}=3\\ y=3\sqrt{x+2}](https://tex.z-dn.net/?f=9%3Dk%5Csqrt%7B7%2B2%7D%3D3k%5C%5C%20k%3D%5Cfrac%7B9%7D%7B3%7D%3D3%5C%5C%20y%3D3%5Csqrt%7Bx%2B2%7D)
Put x = 23
![y=3\sqrt{23+2}=3\sqrt{25}=3(5)=15](https://tex.z-dn.net/?f=y%3D3%5Csqrt%7B23%2B2%7D%3D3%5Csqrt%7B25%7D%3D3%285%29%3D15)
Can you give me a hint? Derivative means to get from another source
Using the z-distribution, it is found that the 90% confidence interval for mean calories in a 30-gram serving of all chocolate chip cookies is (143, 149).
We are given the <em>standard deviation</em> for the population, which is why the <em>z-distribution </em>is used to solve this question.
The information given is:
- Sample mean of
.
- Population standard deviation of
.
- Sample size of
.
The confidence interval is:
The critical value, using a z-distribution calculator, for a <u>95% confidence interval</u> is z = 1.645, hence:
![\overline{x} - z\frac{\sigma}{\sqrt{n}} = 146 - 1.645\frac{12}{\sqrt{35}} = 143](https://tex.z-dn.net/?f=%5Coverline%7Bx%7D%20-%20z%5Cfrac%7B%5Csigma%7D%7B%5Csqrt%7Bn%7D%7D%20%3D%20146%20-%201.645%5Cfrac%7B12%7D%7B%5Csqrt%7B35%7D%7D%20%3D%20143)
![\overline{x} + z\frac{\sigma}{\sqrt{n}} = 146 + 1.645\frac{12}{\sqrt{35}} = 149](https://tex.z-dn.net/?f=%5Coverline%7Bx%7D%20%2B%20z%5Cfrac%7B%5Csigma%7D%7B%5Csqrt%7Bn%7D%7D%20%3D%20146%20%2B%201.645%5Cfrac%7B12%7D%7B%5Csqrt%7B35%7D%7D%20%3D%20149)
The 90% confidence interval for mean calories in a 30-gram serving of all chocolate chip cookies is (143, 149).
A similar problem is given at brainly.com/question/16807970
Answer:
Step-by-step explanation:
If you’re looking for what quadrant (5,-2) would be in, it would be quadrant 4 but you’re looking for when x is -5 and y is positive 2 making it in quadrant 2