This is an example of extrapolation, a humorous and ironic passage from Mark Twain's "Life on the Mississippi:" "In the space of one hundred and seventy-six years the Lower Mississippi has shortened itself two hundred and forty-two miles. That is an average of a trifle over one mile and a third per year. Therefore, any calm person, who is not blind or idiotic, can see that in the Old Oolitic Silurian Period,' just a million years ago next November, the Lower Mississippi River was upwards of one million three hundred thousand miles long, and stuck out over the Gulf of Mexico like a fishing-rod. And by the same token any person can see that seven hundred and forty-two years from now the Lower Mississippi will be only a mile and three-quarters long, and Cairo and New Orleans will have joined their streets together, and be plodding comfortably along under a single mayor and a mutual board of aldermen." Extrapolation means extending known information. Surmise means something much closer to a pure guess, one possibility out of many. Another example, also from Mark Twain, "Is Shakespeare Dead?" "The historians find themselves 'justified in believing' that the young Shakespeare poached upon Sir Thomas Lucy’s deer preserves and got haled before that magistrate for it. But there is no shred of respectworthy evidence that anything of the kind happened. The historians, having argued the thing that might have happened into the thing that did happen, found no trouble in turning Sir Thomas Lucy into Mr. Justice Shallow. They have long ago convinced the world – on surmise and without trustworthy evidence – that Shallow is Sir Thomas."

No. Extrapolating is if you take figures showing past trends and calculate from these what it likely to happen in the future. Surmising means 'guessing/supposing'. You can't surmise figures, so you can't use this word in this sentence.