सदस्य: Melody

mikey123:
explain how you would design an experiment to evaluate whether praying for a hospitalized heart attack patient leads to a speedy recovery. show how you would incorporate comparison, randomization, and blinding.

I have no idea Mikey.
You would be much more likely to get an answer if you post this question in
mathhelpforum.com
You'll have to sign up but I think they have a specific section for statistics and they are very friendly.
They will however expect you to be interactive with your learning. They will probably want you to offer some basic ideas first before they really help.

Sorry, that's the best i can offer.

Melody25 Jan 2014

+118691

brian:
-3{[(-4-1)-(-6^0-2)-1]-1}±Sqrt(9)

okay Brian,
Just do it a bit at a time
-3{[(-4-1)-(-6^0-2)-1]-1}±Sqrt(9)

-4-1=-5 and sqrt(9)=3

-3{[(-5)-(-6^0-2)-1]-1}±3

Now, any non-zero number to the power of 0 = 1
but -6^0 could meant -1*6^0 (that is what my calculator would think) OR it could mean (-6)^0
You really need brackets to make the meaning clear.
I'm just going to choose one and for no particular reason I am going to choose (-6)^0
and (-6)^0 = 1

-3{[(-5)-(1-2)-1]-1}±3
1-2=-1
-3{[(-5)-(-1)-1]-1}±3
so now we have

-3{[ -5--1-1] -1} ± 3
-- = +

-3 {[ -5+1-1] -1} ± 3

-3 { -5-1} ± 3

-3 * -6 ± 3

+18 ± 3

= 18+3 or 18-3
= 21 or 15

Now remember if -6^0 was interpreted as -1*6^0, which it easily could be then the answer would be different.

Melody25 Jan 2014

+118691

harp22:
How do you calculate 250e^ (-0.4) on the graphing calculator?

e is just a number, it is approximately equal to 2.718

So what you have there is just a number. I suppose you could graph it on a number line but I don't think that is what you meant.

You can work out an approximate value for it on any calculator.

250 * shift e (-0.4) = 167.58

I think that you will need to press the shift key on most calculators to bring up the e ^x

I hope that helps

Melody25 Jan 2014

+118691

Hi Anonymous 4338,

thanks to answering questions today.
That one, d=56m
it didn't occur to me that this was a side of length of 56m, but I think you hit the meaning right on the head and that's Excellent!
--------------------------------------------------------------------------------------------------
Now, let's look at your question.

8.1(z+2.3) = 4.9(z-4.2)

first expand th brackets on both sides
8.1z + 8.1*2.3 = 4.9z - 4.9*4.2

8.1z + 18.63 = 4.9z - 20.58
now you need to get all the lots of z on one side and all then numbers without zs on the other side
start by subtracting 18.63 from both sides (whatever you do to one side you have to do to the other side as well)

8.1z + 18.63 - 18.63 = 4.9z - 20.58 - 18.63

8.1z = 4.9z - 39.21
Now subtract 4.9z from both sides

8.1z - 4.9z = 4.9z - 39.61 - 4.9z

(8.1 - 4.9)z = -39.21

3.2z = -39.21
now you just need to get rid of 3.2 the opposite of times 3.2 is divide by 3.2

3.2z / 3.2 = -39.21 / 3.2

z = -12.253125
z = -12.25 (correct to 2 decimal places or correct to 4 significant figures)

There you go. That's how it is done.

Melody25 Jan 2014

+118691

Guest:
How do you get to cos-1?!?!?!?!

Cos -1 of what?

Melody25 Jan 2014

+118691

staciethompson11364:
What are the roots of the quadratic equation x2 - 19x + 84 = 0?

I like Serena is absolutely correct but i want to talk about how he got his answer.
------------------------------------------------------------------------------------------------------------------
What are the roots of the quadratic equation x ² - 19x + 84 = 0?

You have to look for 2 numbers that multiply to give 84 and add to give -19

Since they muliply to give a positive number than they both must have the same sign. Both pos OR both neg
BUT these two numbers have to add to give a negative number so they both must be negative.

Lets look at factors of 84
-2 and -42 ? No they don't add to -19
-12 and -7 ? yes, they add to -19 so they are the numbers that you need.

So we have found that the factors are (x-12) and (x-7) that is
(x-12)(x-7)=0

Now, if two things multiply together to give you zero, then one of them has to equal 0 (or maybe both) therfore,
either x-12=0 or x-7=0
when you solve these little equations you get x=12 or x=7

Melody25 Jan 2014

+118691

JustKidding:
How do I use this calculator to figure out binomial theorem problems?

What calculator? nCr Is probably the same on all calculators.
Maybe you should present a full question and explain what your problems are as best as you are able.

Melody25 Jan 2014

+118691

bechapm:
When dealing with decimals or percents, everything is over 100. For example .25 is just 25/100 which when reduced is 1/4.

bechapm is right for percents that is 13% = 13/100

bechapm is also totally correct for decimal with two decimal places. so 0.13 = 13/100

So 13% = 13/100 = 0.13

But I'd like to talk about other decimals a little

The first number after the point is tenths so 0.6 = 6/10

The second number after the point is hundreths so 0.08 = 8/100

The third one is thousandths etc

If there is more than one digit after the point you just put the whole lot over what the last digit is worth. eg

0.016 The 6 is in the thousandths place so the fraction equivalent is 16/1000

I hope that helps

Melody25 Jan 2014

+118691

TAN:
HOW DO GET INVERSE TAN ON THE KEY BOARD? SHIFT DOES NOT WORK?

Which keyboard ?

inverse tan is the same as arctan, maybe the key that you are looking for is atan ?

Melody25 Jan 2014

+118691

sleepyreverie2:
how do i put it to the 18th power...ex. (1+.04/12)18

On a calculator it is a ^ or an x ^y symbol

so to enter this on a calculator it is just

(1+0.04/12) ^ 18 =

The calculator knows to do the division before it does the addition.

Melody25 Jan 2014

यूजर का नाम	Melody
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