Answer:
(c) 43.
Step-by-step explanation:
Given:
Margin of error (E) = 2
Sample variance 
= 44
Confidence level = 95%
The z- value at 95% confidence level is 1.96.
The sample using the provided information can be calculated as:
Hence, the correct option is (c) 43.
Answer:
Thirteen hundredth
Step-by-step explanation:
Answer:
Elgas is 35.
Step-by-step explanation:
Let's set up an equation.
Alvin is 7 years younger than Elgas.
A = E - 7
The sum of their ages is 63.
A + E = 63
Let's use substitution.
Plug in the first equation of A into the second equation.
A + E = 63
(E - 7) + E = 63
Combine like terms.
2E - 7 = 63
Add 7 to both sides.
2E = 70
Divide both sides by 2.
E = 35
Elgas is 35.
Hope this helps!
Take half of the coefficient of x (which is 2/5) and square it:
[ (1/2)(2/5) ]^2 = (1/5)^2 = 1/25, or 0.04
Thus, to rewrite x^2 + (2/5)x to include a perfect square trinomial,
x^2 + (2/5)x = x^2 + (2/5)x + (1/5)^2 - (1/5)^2, or
(x+1/5)^2 - (1/5)^2, or (x + 1/5)^2 - 1/25
