I started learning statistics recently. I got problem while learning skewness & kurtosis concept i.e in my search for formulas regarding skewness & kurtosis it is showing two different formulas and don't understand when to use which.
And the same problem for kurtosis is also having when to use lengthy formula and when to use small.
can any one please give me clarification,so it is very helpful to me please.
THANKING YOU IN ANTICIPATION
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I want to compare the output of my simulation model to the observed data in various ways, like using an independent t-test to compare the means. However, when I do the independent t-test in SPSS, I get a different result than the independent t-test in Excel. I don't know why so I don't know which one I should use. Can anybody tell me why the results are different?
Here is the independent t-test in SPSS (with t-value 0,181 and p-value 0,857):
Here is the t-test: Two-Sample Assuming Equal Variances in Excel (also the t-test assuming unequal variances is different than the one in SPSS):
After running the TTest on your original data in SPSS, with the FULL data, I got perfectly matching results from spss and excel (see below).
The problem you had has to do with one case seemingly missing from your "observed" set (as noted by #TomSharpe).
This could be due to a simple error in copying the data to SPSS. In SPSS you had to have the two ranges in the same column - you may have done this manually with an error - in which case you should learn to use restructure commands, namely varstocases, to avoid such mistakes.
On the other hand, if the data is full but still a case seems to be missing from the analysis, you should check if the data is weighted by another variable. Weighted data can change the apparent number of observarions in the analysis, and of course change the results.
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Can anybody explain the sigma part of the equation attached for Allan Variance? How Can I calculate this equation in excel?Allan Variance Equation
Quoting the reply from 落雪绽菊.
Different methods will have different formulas for short-term stability measurement, so you have to write several formulas, none of which is universal; the short-term stability measurement usually has a sampling time from 0.001 to 10s. Fortunately, it can be recorded manually, but it cannot be recorded below 1s. To realize manual recording, automatic measurement is generally adopted. Usually, the calculation is completed after this process, and it is of little significance to enter the calculation in execl. Here is the simplest one. If a1:a101 is the data area, enter =SQRT(SUM((A2:A101-A1:A100)^2)/(2*100))
in a certain cell in an array mode.
This is for your reference only. English is not my native language.The text is Google Translated, please excuse typing errors.
I have a set of data say {4,7,7,10,10,12,12,14,15,67} and i want to know the 95th Percentile. I used Excel and Online calculator.
Both gave different answers.
In Excel, formula i used : =PERCENTILE.INC(A1:A10,0.95) and result = 43.6
But this online percentile calculator yielded a result of 67
Which one is right?
First of all, both methods are "right" in the sense that both implement a standard algorithm for computing percentiles. Unlike the mean or median (where all sources use the same approach) there are many different approaches to calculating percentiles. The fundamental issue is that there is no obvious solution to the problem of what to do with percentiles which fall between observations. Do you take the observed value which is closest? Do you interpolate between the two? If so -- with what weighting factors do you do the interpolation? Wikipedia discusses nine (!) with both the Excel approach and the approach from that online percentile calculator making the list. See this paper for a very nice discussion of these algorithms.
You can replicate the functionality of that online percentile function like thus:
=SMALL(A1:A10,CEILING.MATH(COUNT(A1:A10)*0.95))
For example:
The point of using the function SMALL rather than a direct numerical index is that this approach works even if the data isn't sorted.
I'm wanna calculate the Skewness of 10 data(number); But SPSS calculate it differently in multiple computer!!!
The Numbers:
239.00,
176.00,
235.00,
217.00,
234.00,
216.00,
318.00,
190.00,
181.00,
225.00.
I followed this steps:
Analysis--->Descriptive Statistics--->Frequencies--->Statistics--->Skewness--->Continue--->Ok
Answer of SPSS in one pc:
Answer of SPSS in another pc:
I really don't know why? And what should I've done?
Please help me... I need it a lot.
Thanks.
I think that you have the values set to format differently on the second computer, so you are seeing the rounded value. Double click the table, and click in the skewness cell to see the full precision value (or use Format > Cell Properties) to get more decimals. Also, you can compare the mean and variance to make sure that the data is really the same on both.
first of all let me say that my knowledge of Excel is somewhat basic. I know about formulas but not indepth. I know about functions but nothing about programing. That being said, on with my question.
I'm currently building a office hockey pool spread sheet. I have my main sheet, the result of the games and the differential (see link above for reference, text is in french sorry about that). I will have another sheet, prediction sheet, that the participant will fill with their prediction about who's gonna win the game and by how many points (differential).
Now, I need the prediction sheet to calculate the points attribution depending on the prediction.
Here's how it's supposed to calculate:
1 point for winning team prediction (per game)
1 point for good differential (no mather what team won)
2 point if differential is 3 or higher.
User predictions go on "prediction" sheet, they input what they think the diff. will be on the same side as the team they pick to win.
So what I want to know is, what would be the best way to go about this, with a formula or with a custom function in VBA? I need to determine 1: if the prediction is in the same cell as the other sheet and 2: if the differential is the same as the game result.
Ok, re-reading this I know it's kind of confusing, but it's clear in my head... sorry about that. If anyone of you can make sence out of my problem, please help me by guiding me in the right way. Thank you very much.
If found part of my solution.
I used this formula (I know it can be shorter and better but that's the extent of my knowledge in excel):
=IF(OR(ISBLANK(COMPILATION!A4);ISBLANK(COMPILATION!A5));0;IF(OR(A4=ABS(COMPILATION!A4-COMPILATION!A5);A5=ABS(COMPILATION!A4-COMPILATION!A5));IF(OR(A4>=3;A5>=3);2;1);0))