Omega Owners Forum
Chat Area => General Discussion Area => Topic started by: STEMO on 18 June 2017, 14:48:32
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I went up to his room to do something and he told me that he was having trouble getting z tests to work out. 'Keep at it' I said, 'you'll get there'.
So I came down and thought I'd have a quick look to see if I could help. I mean, it's only numbers. So I found this:
A Z-test is any statistical test for which the distribution of the test statistic under the null hypothesis can be approximated by a normal distribution. Because of the central limit theorem, many test statistics are approximately normally distributed for large samples. For each significance level, the Z-test has a single critical value (for example, 1.96 for 5% two tailed) which makes it more convenient than the Student's t-test which has separate critical values for each sample size. Therefore, many statistical tests can be conveniently performed as approximate Z-tests if the sample size is large or the population variance known. If the population variance is unknown (and therefore has to be estimated from the sample itself) and the sample size is not large (n < 30), the Student's t-test may be more appropriate.
If T is a statistic that is approximately normally distributed under the null hypothesis, the next step in performing a Z-test is to estimate the expected value θ of T under the null hypothesis, and then obtain an estimate s of the standard deviation of T. After that the standard score Z = (T − θ) / s is calculated, from which one-tailed and two-tailed p-values can be calculated as Φ(−Z) (for upper-tailed tests), Φ(Z) (for lower-tailed tests) and 2Φ(−|Z|) (for two-tailed tests) where Φ is the standard normal cumulative distribution function.
I think I'll leave him to it ;D
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Whaaaaaat :o :o :o :o :o :o :o ;D
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It all got a bit hazy after "I went"... ???
;D
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Does that stuff have any relevance in the real world? ???
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Does that stuff have any relevance in the real world? ???
Yup. Used for statistically grading samples of anything... grains of rice/rivets/likelihood of resisting a very specific form of cancer based on genetic origin and whether you eat carrots or not/likelihood of any given grade of insulation panel resisting burning below/above any given temperature... which reminds me...
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Its easy, let me explain simply.....
For example..
Each apple weighs 0.25lbs and price of apples is £1.50/lb.
How much are 1kg of bananas?
See easy ::) ;D
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Its easy, let me explain simply.....
For example..
Each apple weighs 0.25lbs and price of apples is £1.50/lb.
How much are 1kg of bananas?
See easy ::) ;D
Statically speaking... :D
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I understood every last word of that oh no wait a minute that should have been I understood the last word ;D ;D ;D
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Does the lad have any idea what he wants to do as a career ste? He seems like a helluva bright chap!
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Does the lad have any idea what he wants to do as a career ste? He seems like a helluva bright chap!
He wants to follow in mummy's footsteps....teaching. I've got about 4 years to convince him of the error of his ways.
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Ha!
You could talk to him about the actuarial profession, and the joys of a 6 figure salary ;D
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Ha!
You could talk to him about the actuarial profession, and the joys of a 6 figure salary ;D
AI will be taking care of all that soon. :P ;D
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A Z test is just a means of getting an indication if a set of results is valid or not
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Whatever happened to......"lf Johnny has two apples and he gives one apple to Jilly (for a quick feel) how many apples and what percentage of the original apples does randy Johnny have left"
Answer......one apple and 50%.
Kids stuff. :)
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Does the lad have any idea what he wants to do as a career ste? He seems like a helluva bright chap!
On his mother's side. :)
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Nice to have a consensus. ;D
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That is it. Last A level done today.
Now..what to do to entertain an 18 year old for nearly 3 months.
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Now..what to do to entertain an 18 year old for nearly 3 months.
If his laptop is working OK, I'm sure he's more than capable of entertaining himself! ;)
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Now..what to do to entertain an 18 year old for nearly 3 months.
If his laptop is working OK, I'm sure he's more than capable of entertaining himself! ;)
I feel guilty if he doesn't get out and about but, I suppose, I shouldn't.
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That is it. Last A level done today.
Now..what to do to entertain an 18 year old for nearly 3 months.
Strippers?
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That is it. Last A level done today.
Now..what to do to entertain an 18 year old for nearly 3 months.
Strippers?
Hmmm...I've been meaning to paint those bannisters....... :-\
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That is it. Last A level done today.
Now..what to do to entertain an 18 year old for nearly 3 months.
Strippers?
That's the first 3 minutes sorted (giving the lad the benefit of the doubt). :y
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That is it. Last A level done today.
Now..what to do to entertain an 18 year old for nearly 3 months.
I can't believe that a red-blooded 18 year old will want to be 'entertained' by an old fart for 3 months. :)
Now that would be sad.
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That is it. Last A level done today.
Now..what to do to entertain an 18 year old for nearly 3 months.
Strippers?
That's the first 3 minutes sorted (giving the lad the benefit of the doubt). :y
Recuperation will be extremely swift for an 18 year old. He'll be ready to go (or watch) in another 15 minutes. ;)
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Now..what to do to entertain an 18 year old for nearly 3 months.
If his laptop is working OK, I'm sure he's more than capable of entertaining himself! ;)
I feel guilty if he doesn't get out and about but, I suppose, I shouldn't.
Time for dad to broarden his educational horizons with a day trip to London and Spearmint Rhinos. ;)
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Just dropped him at the Marriott hotel in Leeds for his end-of-college do. That will keep him going for now. Gotta drive all the way back to pick him up later.