More Stats Problems - exam is nearing?

Some students decided to test the assertion that one cannot tell the difference between butter and a particular brand of margarine. They recorded their results as follows
Could Tell Could not tell
Male 16 14
Female 21 9
To test if there is any significance between the ability of males and females in distinguishing between butter and margarine, the test statistic is equal to
1) 0.13
2) 1.76
3) 1.83
4) 0.17
5) 0.42
Thanks for your help!

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Urgent complex numbers question?

a - 2i -1*(7 + bi) = -4 - 8i
a - 2i - 7 - bi = -4 - 8i
a - bi = -4 + 7 - 8i + 2i
a - bi = 3 - 6i
a = 3 and b = 6.

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Word problem, please help!?

if she has 2 and needs 6, she needs 4 liters of x% solution
2 * .3 + 4x = 6 * .46
.6 + 4x = 2.76
4x = 2.16
x = .54
she needs 4 liters of 54% solution

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Use the least-squares method?

y = c d^x
ln y = ln(c d^x) = ln c + x ln d = A + x B
given data (x,y), convert to (x, ln y) then use the usual linear least squares method to find {A,B}
A = ln c
B = ln d
so by finding {A,B} you find {c,d}

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Why is it called two real and equal roots b^2 - 4ac = 0 when the straight line touches the curve at one point?

b^2 - 4ac = 0, also defined as two real and equal roots (TWO ROOTS) but why for its graph, the U parabola or curve touches the line at only one point (ONE)
Two roots on one point? Senseless. But it will make sense when b^2 - 4ac > 0; two real and distinct roots; intersects at two points.

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Simple Interest Sum need Help?

I = Prt
7200 = Pr * 4
1800 = Pr
you need two numbers when multiplied that equal 1800
pick a random interest rate
6%
1800 = .06P
30000 = P
Rs 30000 invested at 6% interest for 4 years
you pick the other and solve

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Find the coordinates of the vertex for the parabola defined by the given quadratic function.?

7. f(x) = 7 - (x + 4)2
a. (7, 4)
b. (-4, 7)
c. (4, 7)
d. (7, -4)
thank you!
Sorry, I could not read the content fromt this page.
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Is there a way to simplify the left hand-side of this algebra problem to solve for Y? ((60/s)/4)*60 = Y?

Well, I'm not sure how simplified you want it considering you have two variables in this equation. It seems you already did part of it with (60/s)*60 = 4y.
Just multiply 60*60 which = 3600 then divide by 4, which gives you 900s = Y
The other way you could do it was write it as (60/4s)*60 = Y
Just divide 60/4 = 15 then multiply by 60 to give you 900s = Y
I don't know what the value of s is or what the equation represents but that is probably as simplified as you are going to get without any more information.

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Differentiation with complex numbers?

Given f(z)= [(4+2i)z/(2-i)z^2 + 9i]^3, find f'(z).I got an answer by doing the chain rule then the quotient rule. Is that what I'm supposed to do? Can someone provide the correct answer so I can compare mine to see if I did it right? ThanksAnswer QuestionBe the first to answer this question.
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I'm looking for a good math reference?

Hello people out there. Do you know a good reference for geometry and trigonometry? It'd be nice if the book is easy to read and understand with full of details which I have to learn.


thank you :)

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Probability question help!?

Hey there,

I have been faced with this question and I am a little stuck:

An urn initially has one red ball. Persephone uses a device to select n blue balls with
probability (e^−x) x^n)/n!, for n = 0, 1, 2, . . . , and add them to the urn. She then selects
one ball at random from the urn. Show that the probability that she selects the red ball
is (1 − (e^-x) )/ x.

Regards, Seany.

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