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NikRik,
Here is a color coded multiplication table from 1 to 15 that will help you visualize the intersection of the product of 2 numbers on a table:
I want to build a lesson for this, and I started out on Excel. Working this out on a normal distribution Rank-Sum Test, I get n1 = 348, n2 = 174. I get w1 = 90989.5 and w2 = 45519. Using that information and going with the Mann-Whitney test, I get the following:
u1 = 30263.5
u2 = 30294
U = 30263.5
mu = 30276
sigma^2 = 2639058
sigma = 1624.517775
Z = -0.007694591
which gives a probability of 0.49693 from that Z-score.
I ranked ascending grouping by 0's for no disease and 1 for having the disease. Can you provide more information on how you got your #'s?
I WANT YOU TO HELP ME WITH MULTIPLICATION:
eshe,
To see the line by line math and logic behind the multiplication of 2 numbers, see this link:
I have it color coded for you with explanations.
The cafateria was accused of cheating students bynot giving them enough coffee in their 12oz cups. 15 cups were selected randomnly, they had a mean of 11.7 with a std dev of 0.5 at 0.01 significance level the claim that the customers were being cheated.
Thanks in advance.
It sounds like our 0.01 significance level is our 1 - 0.01 = 99% confidence interval. We want to check the confidence interval of a small population (< 35), so we use the Student t-test. We have all 4 inputs to generate the math and answer:
Running the numbers, we get a sample mean of:
11.3157 < μ < 12.0843
We are 99% confident that our mean of 12 ounce cups is inside this interval, so I would say that the students are not being cheated.
Let me know if this explanation makes sense.
Also, if we would have had a large sample size (> 35), we could have used this confidence interval check here:
18 people are randomly selected with a mean score of 550 and a std. dev. of 140. Find the 95% confidence interval for the population variance and std.
can you tell me how i find point estimates for population variance and standard deviation?
Thanks in advance.
Prakash,
This sounds like you can use a Chi-Square Confidence interval. We have our Sample N = 18 and our confidence percentage of 95%. Since standard deviation is 140, squaring that gets us our variance of 19600.
Go here and plug those 3 in:
Chi-Square Confidence Interval for the Variance and Standard Deviation
This will show you every single line of math for how to determine both the variance and standard deviation confidence i nterval. Press either button to see the math work. You will notice about halfway down I provide a shortcut in Microsoft Excel for how to calculate some of the values on the fly if you ever need to.
Let me know if I can provide more assistance.
I disagree, I think the answer is 0.3293
http://www.mathcelebrity.com/poisson.php
Using 1,0.6,1 for your entries since 15/25 = 0.6 and we only use n for the mean which we already have, you can see the math. I think the 1st poster needs to divide by e to the negative lambda. With respect to everything else, I agree with the 1st poster on the math, except the last step.
I say that because the Expanded Notation that you did looks simplified. Go here:
You will see the following by pressing the expanded notation button:
Expanded Notation of 100 = (1 x 10^2) + (0 x 10^1) + (0 x 10^0)
Expanded Notation of 100 = (1 x 100) + (0 x 10) + (0 x 1)
and
Expanded Notation of 200 = (2 x 10^2) + (0 x 10^1) + (0 x 10^0)
Expanded Notation of 200 = (2 x 100) + (0 x 10) + (0 x 1)
I think the teacher meant to simplify the zeros, that was a bit tricky in the way it was worded.
Sounds like a trick question, since standard form is converted into expanded notation and vice versa.
Even 1 is written as 1 * 10^0.
adurr,
A friend of mine is taking an exam similar to what you mention. One of the things he had to study was factor pairs and prime factorization.
I built a lesson here if you need it:
Oh, I see, like a parabola?
Such as y = x^2?
I think the first step is to take your points and make an x/y chart. I usually write down 3-4 points and then see how to write the function.
For example, you have points such as
x y
0 1
1 2
2 5
3 10
You can see that you square x and add 1 to get to y. So your function would be y = x^2 + 1.
Make sense?
The graph's slope.
Great, then you would just enter 2 points on the line in the calculator link I provided and it will show you exactly how to calculate slope.
Let me know if you have questions or want enhancements.
Just started 9th grade Geometry (I'm in an advanced class) and the teacher gave us a small assignment for the night. Summer was long and fun and now I need to "relearn" some bits of Algebra.
Basically, I am supposed to graph some data, I've made all three graphs like directed, but I am required to write a function for each graph that would contain the data points.
So, I really just need to be retaught how to write a function from the results of a graph.
Please respond ASAP.
Thanks!
Are these straight line graphs? If so, you would start by taking 2 of the points on the line, and forming the equation using the point-slope formula. To see a coast to coast demonstration of this, go here:
This shows you how to take 2 points, and form the slope of the line, the line equation, the distance between the 2 points, and the midpoint of the 2 points.
If your graphs involve more than straight lines, let me know. if I don't have the lessons, I can search to find other resources for you.
Do you know where I could find a sample basic math test? that would really be helpful. thanks again for all your help.
Adurr25
They have some basic quizzes there. Start there and see what you think.
I'll be checking back periodically, so if your husband needs items on my site built to help him, let me know.
I'll be working on more random generators later today on the basic math page as well.
I've added a random problem generator to the Fraction lesson just now. If you don't see the button, please refresh your Internet browser. That will generate 2 completely random fractions for him if he runs out of problems from the book to do.
The numerator will never be greater than 10 and the same with the denominator for the randomly generated fractions.
If your husband needs to check his answers as well as see line by line homework problems, feel free to direct him to my basic math page:
It contains addition, subtraction, 2 x 2 multiplication, long division, fractions, proportions, etc.
In addition, if he wants randomly generate problems for basic math, he can use my problem generator located here:
Teacher's Corner Random Problem Generators
If he wants random problems generated for fractions and other subjects, I would be happy to build that on my site for him. The long division lesson has a random problem generator built already.
It would not take me too long to build it for other lessons as well.
As far as other sites that would help his cause, Math.com is a good place to start. That would be good for him to read up on basic math and the principals. My site would be more useful for checking homework and seeing the actual guts of the math behind the answer.
Let me know if I can be of more assistance.
77horses,
If you want a tutorial on fractions, and to check the line by line math work, take a look at my calculator here:
It handles the adding, subtracting, multiplying, and dividing of fractions, both proper and improper, as well as mixed numbers.
Let me know if I can be of any more help.
Hello, my name is Don and I run the site www.mathcelebrity.com.
I'm going to commit time to answering math questions and providing a resource for automated solutions to check answers/homework.
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