Answer:
third option
Step-by-step explanation:
Given
x² + 4x - 4 = 0 ( add 4 to both sides )
x² + 4x = 4
Using the method of completing the square
add ( half the coefficient of the x- term )² to both sides
x² + 2(2)x + 4 = 4 + 4, that is
(x + 2)² = 8 ( take the square root of both sides )
x + 2 = ±
= ± 2
( subtract 2 from both sides )
x = - 2 ± 2
Step-by-step explanation:
no,yes,no, d is probably yes I guess
Answer:
90% confidence interval for the population mean is between a lower limit of $92.18 and an upper limit of $107.82.
Step-by-step explanation:
Confidence interval for a population mean is given as mean +/- margin of error (E)
mean = $100
sd = $25.20
n = 30
degree of freedom = n-1 = 30-1 = 29
confidence level (C) = 90% = 0.9
significance level = 1 - C = 1 - 0.9 = 0.1 = 10%
critical value (t) corresponding to 29 degrees of freedom and 10% significance level is 1.699
E = t×sd/√n = 1.699×25.20/√30 = $7.82
Lower limit of population mean = mean - E = 100 - 7.82 = $92.18
Upper limit of population mean = mean + E = 100 + 7.82 = $107.82
90% confidence interval is ($92.18, $107.82)
I think its C but I could be wrong.
I hope this helps :)
2n+2(n-4)=56
2n+2n-8=56
4n-8=56
4n=64
n=16
1st side is 16
2nd side is 12