Answer: 240
Formula:
n = [(z-value * sd)/E]^2
where n = sample size,
z-value will be 2.58 using a z-table to represent the 99% confidence interval
sd(standard deviation) = 3
E = 0.5
Substituting the parameters into the formula n = [(z-value * sd)/E]^2, we have,
n = [(2.58 ×3) ÷ 0.5]²
n = 239.63 approximately 240.
True. Hopefully this helps. Sorry if I’m wrong.
Answer:
5
Explanation:
(2x – 4)² – 5 = 31
Adding 5 to both sides gives
(2x – 4)² – 5+5 = 31+5
(2x – 4)² = 36
(2x – 4) = √36
2x-4 = 6
Adding 4 to both sides gives
2x-4+4=6+4
2x= 10
Divide through by 2
2x/2 = 10/2
X= 5.