Answer:
Step-by-step explanation:
(1) 2x - 6y = -12
(2) x + 2y = 14
There is a -6y and a +2y. Since they have opposite signs, I'll try to eliminate the y terms. (That's my choice. There is more than one way to solve these.)
Multiply eq. (2) by 3:
3x + 6y = 42
Then add the result to eq. (1) to eliminate the y terms:
2x - 6y = -12
3x + 6y = 42
------------------
5x = 30, so x = 6
Now plug the value of x into eq. (2) and solve for y:
6 + 2y = 14
2y = 8
y = 4
Why did I use eq. (2) to solve for y? Because it's less work. I could have used eq. (1) instead:
2(6) - 6y = -12
12 - 6y = -12
-6y = -24
y = 4
More than one way to solve.
Answer:
Only option d is not true
Step-by-step explanation:
Given are four statements about standard errors and we have to find which is not true.
A. The standard error measures, roughly, the average difference between the statistic and the population parameter.
-- True because population parameter is mean and the statistic are the items. Hence the differences average would be std error.
B. The standard error is the estimated standard deviation of the sampling distribution for the statistic.
-- True the sample statistic follows a distribution with standard error as std deviation
C. The standard error can never be a negative number. -- True because we consider only positive square root of variance as std error
D. The standard error increases as the sample size(s) increases
-- False. Std error is inversely proportional to square root of n. So when n decreases std error increases
Cross section is a surface that is exposed after slicing or making a cut through an object. If a hexagonal pyramid is cut horizontally then the cross section should be an hexagon as well since the base is a hexagon. However, when it is cut vertically the resulting shape would be a triangle.
Answer: 6/37
Step-by-step explanation:
