The phrase "a margin of roughly" is correct and usable in written English.
It can be used when discussing estimates, approximations, or differences in measurements or values.
Example: "The project is expected to be completed with a margin of roughly two weeks behind schedule."
Alternatives: "an approximate margin of" or "a margin of about".
A poll found Democrats thought she beat her top competitor by a margin of roughly two to one.
In a fourth and final ballot, he lost to his younger brother, by a margin of roughly 51 percent to 49 percent.
Britain followed suit: Leave won a victory by a margin of roughly fifty-two per cent to forty-eight per cent, despite a heavy backing for Remain in London, Northern Ireland, and Scotland.
In 1973, Edward Heath, the Conservative Prime Minister of the day, led Britain into the European Economic Community, as it was then called, and in a referendum two years later, the public endorsed Britain's membership by a margin of roughly two to one.
Android handsets, made by several different manufacturers, outsell Apple's iPhone by a margin of roughly three to one, although Apple still takes most of the profits.
For another point of reference, consider that the latest iPod touch probably costs somewhere around $150 to make (an estimate based on the BOM of past iterations), and retails for $299, providing a margin of roughly $150.
In combination with GPA the HAM-Nat improved prediction of success by a margin which was of roughly the same size as the contribution provided by GPA alone.
In Iowa this week, women 29 and younger voted for Clinton's challenger, Sen. Bernie Sanders, by a stunning margin of roughly 6 to 1, much as young men did, according to the poll of voters arriving at precinct caucuses conducted for the television networks and the Associated Press.
Hence, at a confidence level of 95%% our system has an error margin of roughly 0.0155 × 300,000 = 4650 people during peak times.
Setting n = 4,000 leads to M E p = 0.0155 – an error margin of roughly 1.5%%.
Overall results carry a margin of sampling error of roughly 2.5 percentage points; the error margin for subgroups is larger.
