Hello Rolayo Toyin Emmanuel. It sounds as if you have n = 7 data points. Can you share them with us? And can you explain in words (without talking about tests or statistical significance) what your research question is? Thanks for clarifying.

Thank you @Bruce Weaver.

I have elevation (m) data:

Ala 174, Olo 187, Fale 165, Kose 270, Ara 270, Aiye 341, and Sali 337.

Though the highest value is obvious, I want to suport that with a statistical analysis to generate a p-value.

You could use Chebyshev’s Theorem (that works for any distribution; other ways need some assumption about the distribution, what you likely don't have). You don't need SPSS for that. Any software that allows you to calculate the variance or the standard deviation of your data will do (you could do this even with paper and pencil, for just 7 values!).

I don't understand what you mean by: "which of the elevation value is statistically significant"? What is the hypothesis that you are testing? Do you have some kind of estimate for the reliability of the elevation measurements? That could allow "p-values", but I don't see why. Is all you are trying to say that Aiye and Sali are higher than Ara and Kose which are higher than Ala and Olo and Fale, I don't understand why you would want p-values.

If I follow, you want to state that the elevation for Aiye (341) is greater than the elevation some (or maybe all) of the other locations, and you want to report a p-value. Is that right? If so, I see no sensible way to do that--at least not when you have just one measurement of elevation per location. Why do you think a p-value is needed? Can you point to examples where others in your field have reported p-values for examples like this? Thanks.

NOTE: This was posted before I saw the replies from @Jochen Wilhelm & @Daniel Wright. (And apparently @name does not work normally when one is editing a reply!)

If the values are a random sample from some (statistical) population (with some specific but unknown distribution), I find it legitimate to test the hypothesis that a particular value is from this population. For a "usual" test one calculated a test statistic (which is a simple value), and finds the tail probability of this value from a sampling distribution as the p-value. This is not different here: the "test statistic" is the observed value itself, and the distribution is the population distribution. This is nothing but an outlier test (Grubbs test and alikes work similarily, but are based on the assumtion that the distribution is normal).

To make that clear: I don't see how the question is meaningful for the 7 elevation values. I don't think that this is a random sample and even if it was I don't see how it could be contain "outliers". This would require to either have a (possible) inconsistency in the selection process or a possible difference in data generation process (different geological histories? - and how is this related to the sampling?).

One question would be if Rolayo Toyin Emmanuel asked---prior to knowing anything about the altitudes of these places---if one called Aiye was higher than others, but this is different from asking if the observed highest one is higher than the others (the amount higher being "significant" [whatever the questioner means by this] or higher by say more than a certain amount). This seems like what is in the original question, so this depends on what the assumed distribution is, which we'd need to know. And all this depends on why these were sampled. Without this information it seems worth waiting to provide any answers.

Thank you all the responses. A senior collegue insited that the higher values must be proven as statistically higher. I've sought way to do thst and redolved to coming here.

I'm taking all the replies back to her.

Gracias!!