8/9x + 3
• Make 1/3 into 8/9 by multiplying it by 3/3
• add -1 and 4 to get 3
Answer:
49
Step-by-step explanation:
Given:
Width = 0.4
Let's take the z value of 95% which is = 1.96
Let's assume population proportion p1 and p2 = 0.5
For margin of error E, the relation between the width and margin of error is 2E.
i.e 2E = 0.4
E = 0.2
To find the sample size, n, let's use the formula :
= 48.02
≈ 49
(5x - 3y =23) + (7x +3y = -11) =
12x = 12
x = 1
Substitute
5(1) -3y =23
5 - 3y = 23
-3y = 18
y = -6
x=1 and y=-6