Answer:
its the second one
Step-by-step explanation:
So hmmm x²+6x+8=0
alrite.. let's do some grouping now
( x² + 6x + [?]²) + 8 = 0
notice above, we have a missing fellow in order to get a perfect square trinomial... hmm who would that be?
let's take a peek at the middle guy of the trinomial.. 6x.. hmmm let's factor it, 2*3*x, wait a minute! 2 * 3 * x... we already have x² on the left-side, since the middle term is just 2 * the square root of the other two terms, that means that the guy on the right, our missing guy must be "3"
alrite, let's add 3² then, however, bear in mind that, all we're doing is borrowing from our very good friend Mr Zero, 0
so if we add 3², we also have to subtract 3², let's do so
(x² + 6x +3² - 3²) + 8 = 0
(x² + 6x +3²) + 8 - 3² = 0
(x+3)²=3² - 8
(x+3)² = 1
23 since the pattern rules is that we subtract by 3 each time
Answer: The point estimate for the mean weight of all spawning Chinook salmon in the Columbia River is the mean weight from your sample 
= 31.2 pounds .
Step-by-step explanation:
The weights of spawning Chinook salmon in the Columbia river are normally distributed.
Given : The mean weight from your sample is 31.2 pounds with a standard deviation of 4.4 pounds.
The point estimate for the mean 
weight of all spawning Chinook salmon in the Columbia River is the mean weight from your sample i.e. is 31.2 pounds because the best point estimate for population mean is the sample mean. [in normal distribution]
Answer:
Step-by-step explanation:
Let the equal number of hours be represented by variable H;
The two equations will be as follows;
Jack; 40 +30H
Mark; 50 +25H
Next, equate them;
40 + 30H = 50 + 25H
30H - 25H = 50 - 40
5H = 10
H =10/5
H = 2hrs
Therefore, they charge the same amount at 2 hrs.
B.) The amount charged;
Replace the variable H in any of the two equations above with 2 to solve for the amount.
Equation 40+30H = 40 + (30*2)
=40 + 60
= $100
