Answer:
-1
Step-by-step explanation:
The answer is b, -1.
I do not have a step by step explanation for that.
OK. I did it. Now let's see if I can go through it without
getting too complicated.
I think the key to the whole thing is this fact:
A radius drawn perpendicular to a chord bisects the chord.
That tells us several things:
-- OM bisects AB.
'M' is the midpoint of AB.
AM is half of AB.
-- ON bisects AC.
'N' is the midpoint of AC.
AN is half of AC.
-- Since AC is half of AB,
AN is half of AM.
a = b/2
Now look at the right triangle inside the rectangle.
'r' is the hypotenuse, so
a² + b² = r²
But a = b/2, so (b/2)² + b² = r²
(b/2)² = b²/4 b²/4 + b² = r²
Multiply each side by 4: b² + 4b² = 4r²
- - - - - - - - - - -
0 + 5b² = 4r²
Repeat the
original equation: a² + b² = r²
Subtract the last
two equations: -a² + 4b² = 3r²
Add a² to each side: 4b² = a² + 3r² . <=== ! ! !
x^2 = 7x - 10
x^2 - 7x + 10 = 0
(x - 5)(x - 2) = 0
x = 5 or x = 2
The answer is B.
The 99% confidence interval for the true mean is given by:
where:
is the sample mean = 69.7
is the standard deviation = 2.8
is the test statistics = 2.58 for for 99% confidentce interval.
n is the sample size = 772.
Therefore, the 99% confidence interval is:
