>>>>My cte only uses the original where - it does not restrict records based on the distance. I do need the final where clause.
>>>
>>>
>>>I give up
>>
>>One of us have some misunderstanding - I suppose it's you in this case.
>
>
>Of course it's me
>
>Count the number of fimes the number 250 occurs in your answer

Can you explain me what does this condition mean

WHERE (Latitude>=@Latitude3-250/111.0 AND Latitude<=@Latitude4+250/111.0) AND
  (Longitude>=@Longitude2-250/111.0 AND Longitude<=@Longitude3+250/111.0)) 

In other words, what exactly this condition is doing?

I think it's building a rectange and then we can filter based on the actual distance. Although what are all the numbers here and constants, it's not clear.