Hi there!
»»————- ★ ————-««
I believe your answer is:
No, it is not a function.
»»————- ★ ————-««
Here’s why:
⸻⸻⸻⸻
- If we preform a vertical line test on the graph, then the line would pass the relation multiple times. This means that it is not a function.
- See the picture attached.
⸻⸻⸻⸻
»»————- ★ ————-««
Hope this helps you. I apologize if it’s incorrect.
Well it depends on what you're working with if it's a large or smaller number of choice.
Answer:
a) The probability of obtaining a sample mean that is less than or equal to 1770 hours is P(M≤1770)=0.0013.
b) It is unusual, as there are only 13 chances in 10,000 (0.13%) of having this outcome.
Step-by-step explanation:
We have a population lifetime with mean of 1800 hours and standard deviation of 100 hours.
Samples of size n=100 are taken and tested.
We can calculate the probability of obtaining a sample mean that is less than or equal to 1770 hours using a z-score for the sample Mean M=1770 and then calculating its probability according to the standard normal distribution:
![z=\dfrac{X-\mu}{\sigma/\sqrt{n}}=\dfrac{1770-1800}{100/\sqrt{100}}=\dfrac{-30}{10}=-3\\\\\\P(X](https://tex.z-dn.net/?f=z%3D%5Cdfrac%7BX-%5Cmu%7D%7B%5Csigma%2F%5Csqrt%7Bn%7D%7D%3D%5Cdfrac%7B1770-1800%7D%7B100%2F%5Csqrt%7B100%7D%7D%3D%5Cdfrac%7B-30%7D%7B10%7D%3D-3%5C%5C%5C%5C%5C%5CP%28X%3C1770%29%3DP%28z%3C-3%29%3D0.0013)
We have f(x) = 0;
Then x^2 - 1 - 2x - 2 = 0;
(x - 1)(x + 1) - 2(x + 1) = 0;
(x + 1)(x - 1 - 2) = 0;
(x + 1)(x - 3) = 0;
x + 1 = 0 or x - 3 = 0;
x = -1 or x = 3;
The zeroes of f are -1 and 3.