Answer:
-21
Step-by-step explanation:
-3 * 7
Answer:
The answer is she lost 9 matches
Step-by-step explanation:
Answer:
![\bar X_B = \frac{\sum_{i=1}^5 X_i}{5} =\frac{500+200+250+275+300}{5}=\frac{1525}{5}=305](https://tex.z-dn.net/?f=%20%5Cbar%20X_B%20%3D%20%5Cfrac%7B%5Csum_%7Bi%3D1%7D%5E5%20X_i%7D%7B5%7D%20%3D%5Cfrac%7B500%2B200%2B250%2B275%2B300%7D%7B5%7D%3D%5Cfrac%7B1525%7D%7B5%7D%3D305)
![s_B = \sqrt{\frac{\sum_{i=1}^5 (X_i-\bar X)^2}{n-1}}=\sqrt{\frac{(500-305)^2 +(200-305)^2 +(250-305)^2 +(275-305)^2 +(300-305)^2)}{5-1}} = 115.108](https://tex.z-dn.net/?f=%20s_B%20%3D%20%5Csqrt%7B%5Cfrac%7B%5Csum_%7Bi%3D1%7D%5E5%20%28X_i-%5Cbar%20X%29%5E2%7D%7Bn-1%7D%7D%3D%5Csqrt%7B%5Cfrac%7B%28500-305%29%5E2%20%2B%28200-305%29%5E2%20%2B%28250-305%29%5E2%20%2B%28275-305%29%5E2%20%2B%28300-305%29%5E2%29%7D%7B5-1%7D%7D%20%3D%20115.108)
![\bar X_A = \frac{\sum_{i=1}^5 X_i}{5} =\frac{-500+200+250+275+300}{5}=\frac{525}{5}=105](https://tex.z-dn.net/?f=%20%5Cbar%20X_A%20%3D%20%5Cfrac%7B%5Csum_%7Bi%3D1%7D%5E5%20X_i%7D%7B5%7D%20%3D%5Cfrac%7B-500%2B200%2B250%2B275%2B300%7D%7B5%7D%3D%5Cfrac%7B525%7D%7B5%7D%3D105)
![s_A = \sqrt{\frac{\sum_{i=1}^5 (X_i-\bar X)^2}{n-1}}=\sqrt{\frac{(-500-105)^2 +(200-105)^2 +(250-105)^2 +(275-105)^2 +(300-105)^2)}{5-1}} = 340.221](https://tex.z-dn.net/?f=%20s_A%20%3D%20%5Csqrt%7B%5Cfrac%7B%5Csum_%7Bi%3D1%7D%5E5%20%28X_i-%5Cbar%20X%29%5E2%7D%7Bn-1%7D%7D%3D%5Csqrt%7B%5Cfrac%7B%28-500-105%29%5E2%20%2B%28200-105%29%5E2%20%2B%28250-105%29%5E2%20%2B%28275-105%29%5E2%20%2B%28300-105%29%5E2%29%7D%7B5-1%7D%7D%20%3D%20340.221)
The absolute difference is:
![Abs = |340.221-115.108|= 225.113](https://tex.z-dn.net/?f=%20Abs%20%3D%20%7C340.221-115.108%7C%3D%20225.113)
If we find the % of change respect the before case we have this:
![\% Change = \frac{|340.221-115.108|}{115.108} *100 = 195.57\%](https://tex.z-dn.net/?f=%20%5C%25%20Change%20%3D%20%5Cfrac%7B%7C340.221-115.108%7C%7D%7B115.108%7D%20%2A100%20%3D%20195.57%5C%25)
So then is a big change.
Step-by-step explanation:
The subindex B is for the before case and the subindex A is for the after case
Before case (with 500)
For this case we have the following dataset:
500 200 250 275 300
We can calculate the mean with the following formula:
![\bar X_B = \frac{\sum_{i=1}^5 X_i}{5} =\frac{500+200+250+275+300}{5}=\frac{1525}{5}=305](https://tex.z-dn.net/?f=%20%5Cbar%20X_B%20%3D%20%5Cfrac%7B%5Csum_%7Bi%3D1%7D%5E5%20X_i%7D%7B5%7D%20%3D%5Cfrac%7B500%2B200%2B250%2B275%2B300%7D%7B5%7D%3D%5Cfrac%7B1525%7D%7B5%7D%3D305)
And the sample deviation with the following formula:
![s_B = \sqrt{\frac{\sum_{i=1}^5 (X_i-\bar X)^2}{n-1}}=\sqrt{\frac{(500-305)^2 +(200-305)^2 +(250-305)^2 +(275-305)^2 +(300-305)^2)}{5-1}} = 115.108](https://tex.z-dn.net/?f=%20s_B%20%3D%20%5Csqrt%7B%5Cfrac%7B%5Csum_%7Bi%3D1%7D%5E5%20%28X_i-%5Cbar%20X%29%5E2%7D%7Bn-1%7D%7D%3D%5Csqrt%7B%5Cfrac%7B%28500-305%29%5E2%20%2B%28200-305%29%5E2%20%2B%28250-305%29%5E2%20%2B%28275-305%29%5E2%20%2B%28300-305%29%5E2%29%7D%7B5-1%7D%7D%20%3D%20115.108)
After case (With -500 instead of 500)
For this case we have the following dataset:
-500 200 250 275 300
We can calculate the mean with the following formula:
![\bar X_A = \frac{\sum_{i=1}^5 X_i}{5} =\frac{-500+200+250+275+300}{5}=\frac{525}{5}=105](https://tex.z-dn.net/?f=%20%5Cbar%20X_A%20%3D%20%5Cfrac%7B%5Csum_%7Bi%3D1%7D%5E5%20X_i%7D%7B5%7D%20%3D%5Cfrac%7B-500%2B200%2B250%2B275%2B300%7D%7B5%7D%3D%5Cfrac%7B525%7D%7B5%7D%3D105)
And the sample deviation with the following formula:
![s_A = \sqrt{\frac{\sum_{i=1}^5 (X_i-\bar X)^2}{n-1}}=\sqrt{\frac{(-500-105)^2 +(200-105)^2 +(250-105)^2 +(275-105)^2 +(300-105)^2)}{5-1}} = 340.221](https://tex.z-dn.net/?f=%20s_A%20%3D%20%5Csqrt%7B%5Cfrac%7B%5Csum_%7Bi%3D1%7D%5E5%20%28X_i-%5Cbar%20X%29%5E2%7D%7Bn-1%7D%7D%3D%5Csqrt%7B%5Cfrac%7B%28-500-105%29%5E2%20%2B%28200-105%29%5E2%20%2B%28250-105%29%5E2%20%2B%28275-105%29%5E2%20%2B%28300-105%29%5E2%29%7D%7B5-1%7D%7D%20%3D%20340.221)
And as we can see we have a significant change between the two values for the two cases.
The absolute difference is:
![Abs = |340.221-115.108|= 225.113](https://tex.z-dn.net/?f=%20Abs%20%3D%20%7C340.221-115.108%7C%3D%20225.113)
If we find the % of change respect the before case we have this:
![\% Change = \frac{|340.221-115.108|}{115.108} *100 = 195.57\%](https://tex.z-dn.net/?f=%20%5C%25%20Change%20%3D%20%5Cfrac%7B%7C340.221-115.108%7C%7D%7B115.108%7D%20%2A100%20%3D%20195.57%5C%25)
So then is a big change.
The depth of the swimming pool that is filled to the top is; 4 m
<h3>Snell's Law</h3>
I have attached a schematic diagram showing this question.
The correct width of the pool is 4 meters. Thus; w = 4 m
Incident Angle; θ₁ = 20°
A right angle is 90° and so the angle θ₂ is calculated from;
θ₂ = 90° - θ₁
θ₂ = 90° - 20°
θ₂ = 70°
We can use snell's law formula to find θ₃.
Thus;
n₁sinθ₂ = n₂sinθ₃
where;
n₁ is refractive index of air = 1
n₂ is refractive index of water = 1.33
Thus;
1*sin 70 = 1.33*sin θ₃
sin θ₃ = (sin 70)/1.33
Solving this gives;
θ₃ = 44.95°
By usage of trigonometric ratios we can find the depth of the pool using;
w/d = tan θ₃
Thus;
d = w/(tan θ₃)
d = 4/(tan 44.95)
d ≈ 4 m
Read more about Snell's Law at; brainly.com/question/10112549