A) The question would be "Does cell phone use time correlate to brain cancer?". The population is all cell phone users. The sample is the 469 people with brain cancer, and the 422 healthy people.
B) This sample size may not portray the entire population of users because the positive results may have been fabricated by factors other than cell phone use. You would have to figure out the population size and determine the correct sample size.
C) This study may not portray cell phone use correlation over a large population efficiently because of the sample size and the predetermined conclusion that cell phone use causes cancer.
Answer:
The y-value is -20
Step-by-step explanation:
So let's solve this by Elimination method;
-2(4x + 5y = -12)
4(2x + 3y = -16)
Let's Distribute;
-8x - 10y = 24
8x + 12y = -64
So x cancels out because -8 + 8 = 0
-10y + 12y = 2y
24 - 64 = -40
2y = -40
Divide both sides by 2;
y = -20
Now lets plug in y to find the value of x;
4x + 5(-20) = -12
4x - 100 = -12
Add 100 to both sides;
4x = 88
Divide both sides by 4;
x = 22
One way to solve this is to use Pythagorean theorem: the square of one leg of triangle plus square of other leg of the triangle equals c the hypotenuse (longest side of triangle). You might see this as the formula a^2 + b^2 = c^2, where a and b are the legs and c is the hypotenuse.
In this case, the legs are 3√2 and the hypotenuse is h.
Using the formula:
(3√2)² + (3√2)² = h²
18 + 18 = h²
h = 6
The other way to do this is with trigonometric angles.
Remember cosine is adjacent over hypotenuse.
cos(45°) = (3√2) / h
h = (3√2) / cos(45°)
h = 6
Answer:
B. Pyramid
Step-by-step explanation:
