Answer:
F and B (as far as I can see).
Step-by-step explanation:
First, let's simplify the equation. You can easily do this by dividing by -4.
-4x < 20
/-4 /-4
x > -5
REMEMBER- Whenever dividing or multiplying a negative number with inequalities, the sign flips!!
On A, we can see that it has a negative symbol, but if we were to divide that, the sign would flip, making -5 greater than x. That's not what we want.
On B, the 20 is negative instead of the 4. Does this change anything?
4x > -20
/4 /4
x > -5
Nope! It still simplifies to what we had at the beginning so it works!
C and D are slightly confusing me because, well, I don't really see how it's relevant to anything so... It doesn't even have a inequality symbol so I don't know lol.
E is wrong because we need the 5 to be positive.
F is obviously right compared to our first answer.
Answer:
(12.1409, 14.0591
Step-by-step explanation:
Given that Tensile strength tests were performed on two different grades of aluminum spars used in manufacturing the wing of a commercial transport aircraft. From past experience with the spar manufacturing process and the testing procedure, the standard deviations of tensile strengths are assumed to be known.
Group Group One Group Two
Mean 87.600 74.500
SD 1.000 1.500
SEM 0.316 0.433
N 10 12
The mean of Group One minus Group Two equals 13.100
standard error of difference = 0.556
90% confidence interval of this difference:

t = 23.5520
df = 20
Answer:
36 percent I think ya
Step-by-step explanation:
I think I should know this