1/4 = 5/20
2/5 = 8/20
8/20 + 5/20 = 13/20 has been spent
Easiest way is if you substitute each point (x,y) into each set of equations and both points work for both equations in the system of equations, then it is the correct answer
Otherwise substitute one equation for y in the other equation:
2x + 6 = x^2 + 5x + 6
-2x - 6. -2x -6
0 = x^2 + 3x. Factor
0 = x (x + 3)
Solve: x = 0. x + 3 = 0. ——> x = -3. Substitute into one original equation to get y value for
y = 2x + 6.
y = 2(0) + 6. y = 2(-3) + 6
y = 6. y = -6 + 6 —-> y = 0
(0 , 6) And. (-3 , 0)
20 - 2n
Difference means taking away
Two times a number means whatever n is it is multiples by 2 and subtracted from 20
Answer:
A sample size of 345 is needed so that the confidence interval will have a margin of error of 0.07
Step-by-step explanation:
In a sample with a number n of people surveyed with a probability of a success of 
, and a confidence level of 
, we have the following confidence interval of proportions.
In which
z is the zscore that has a pvalue of 
.
The margin of error of the interval is given by:
In this problem, we have that:
99.5% confidence level
So 
, z is the value of Z that has a pvalue of 
, so 
.
Using this estimate, what sample size is needed so that the confidence interval will have a margin of error of 0.07?
This is n when M = 0.07. So
A sample size of 345 is needed so that the confidence interval will have a margin of error of 0.07
Answer:
y = -2x + 5
Step-by-step explanation:
Given:
Passes through point (1, 3)
Perpendicular to x – 2y = -8
Solve:
x – 2y = -8
y = 1/2x + 4
The slope is m = 1/2
The slope of the perpendicular line is the inverse of the slope of the original equation.
The slope of the inverse equation is m = -2.
Making an inverse equation of y = -2x + a
Find a:
Use point, (1, 3) where (x, y):
3 = (-2)*(1) + a
a = 5
y = -2x + 5
