Standard error (SE)

Or

Therefore, SE of the mean = (8)/(2) =4
Answer:
45 percent
Step-by-step explanation:
20-11=9
9 divided by 20= 0.45
0.45 x 100= 45%
I think the third one on both part a and b can't be used to find the answer
either $0.50 × $1 or $0.50÷ $1 hope this answer helps