Answer:
x = (-7 ±√89)/4 . . . . . the inverse of selection 3.)
Step-by-step explanation:
You have a quadratic ax²+bx+c=0 with a=2, b=7, c=-5. The solution is given by the quadratic formula as ...
... x = (-b ±√(b² -4ac))/(2a)
Putting your values into the formula gives ...
... x = (-7 ±√(7²-4(2)(-5)))/(2(2))
... x = (-7 ±√89)/4
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<em>Comment on answer choices</em>
For whatever reason, the answer choices appear to be "upside down," with numerator and denominator interchanged. The notation a/b means "a divided by b", which is to say that "b" is the denominator.
U . v = |u| . |v| cos 60 = 10 * 8 * 0.5 = 40 This is called the scalar (or dot) product.
I think it is "More teens play soccer than any other sport"
Fun. I prefer Oxymetazoline.
For the control group we have a headache probability of
c = 368/1671 = .220
For the experimental group we have a headache probability of
e = 494/2013 = .245
The observed difference is
d = e - c = .025
The variance of the difference is
s² = c(1-c)/n₁ + e(1-e)/n₂
so the standard deviation is

We get a t statistic on the difference of
t = d/s = .025/.0139 = 1.79
We're interested in the one sided test, P(d > 0). We have enough dfs to assume normality. We look up in the standard normal table
P(z < 1.79) = .96327
so
p = P(z > 1.79) = 1 - .96327 = 0.037 = 3.7%
Answer: That's less that 10% so we have evidence to conclude that headaches are significantly greater in the experimental group.
Answer:
B.
Step-by-step explanation:
The ratio of Claire's songs to her mother's songs = 3 : 2
A.
3 : 2 = 3/2
9 : 6 = 9/6 = 3/2
12 : 10 = 12/10 = 6/5
B.
3 : 2 = 3/2
6 : 4 = 6/4 = 3/2
15 : 10 = 15/10 = 3/2
C.
3 : 2 = 3/2
4 : 3 = 4/3
5 : 4 = 5/4
D.
3 : 2 = 3/2
4 : 6 = 4/6 = 2/3
20 : 30 = 20/30 = 2/3
The table which shows the correct ratio and two equivalent ratios is B