"a single conclusion" is correct and usable in written English.
You can use it to refer to a conclusion reached after analyzing a particular problem, issue, or set of information. For example: "After careful consideration of the evidence, we reached a single conclusion: that the new policy should be implemented as soon as possible."
The evidence in Thailand seemed to point toward a single conclusion.
In her hands, the fragmented evidentiary record became a seamless narrative tending inexorably toward a single conclusion.
All this adds to a single conclusion: legislators must do something drastic during their current special session on property taxes.
An O.E.C.D. economist acknowledged the nuances in taking into account government regulatory and related factors, and said it was hard to draw a single conclusion from the data.
Many fans felt let down by the lack of a single conclusion, but this has left the show more open to a reboot.
But if there is a single conclusion to be drawn from the two books, it is that the revenge-seeking showoff and the ideal son-in-law both required understanding.
He defines the notion of a single-conclusion quasi-consequence (q-consequence) relation.
A unary connective $*$ is a perfect negation with respect to a single-conclusion consequence relation $\vdash $from the syntactic point of view if the relation $\vdash$ is strongly symmetrical with respect to $*$.
The physiotherapist reached a single diagnostic conclusion in 163 (76%) of cases and two conclusions in 53 cases.
The academic-style discourse would drag on for hours without producing a single concrete conclusion; it would yield only increasingly esoteric questions".
Hence to progress multiple experiments must be undertaken per hypothesis and the subsequent results effectively combined to produce a single reliable conclusion.
