Try this option:
1. if 8*x²+b*x+3=8*x²+p*x+q*x+3, then ⇒ b=p+q.
2. p*q = max_value (b²/2), if p=q=0.5*b, and p*q→-oo, if p>0 and q<0 or p>0 q<0.
3. example:
given 8x²+10x+3, the student rewrites it as a) 8x²+5x+5x+3 (5*5=25-max value); b) 8x²+0.01x+9.99x+3 (9.99*0.01=0.0999→0); c) 8x²-20x+30x+3 (p*q=-600).
answer: (-oo;0.5b²)
Answer and Step-by-step explanation:
we have the following data:
Point estimate = sample mean = \ bar x = 12.39
Population standard deviation = \ sigma = 3.7
Sample size = n = 177
a) the margin of error with a 90% confidence interval
α = 1 - 90%
alpha = 1 - 0.90 = 0.10
alpha / 2 = 0.05
Z \ alpha / 2 = Z0.05 = 1,645
Margin of error = E = Z \ alpha / 2 * (\ sigma / \ sqrtn)
we replace:
E = 1.645 * (3.7 / \ sqrt177)
Outcome:
E = 0.46
b) margin of error with a 99% confidence interval
α = 1-99%
alpha = 1 - 0.99 = 0.01
alpha / 2 = 0.005
Z \ alpha / 2 = Z0.005 = 2,576
Margin of error = E = Z \ alpha / 2 * (\ sigma / \ sqrtn)
we replace:
E = 2,576 * (3.7 / \ sqrt177)
Outcome:
E = 0.72
c) A larger confidence interval value will increase the margin of error.
