These poll results came out before the State Department issued their favorable report:
A slight majority of Americans favor the controversial Keystone XL oil pipeline that President Obama is expected to approve or reject this year, finds a poll conducted for USA TODAY.
About 56% say they favor the northern leg of the billion-dollar, Canada-to-U.S. project and 41% oppose it, according to the poll of 801 U.S. adults completed last month by Stanford University and Resources for the Future (RFF), a non-partisan research group.
More men (60%) than women (53%) support the 1,179-mile pipeline extension, which would carry heavy tar sands from Alberta through Montana and South Dakota to Steele City, Neb. Support was consistent regardless of education level but much stronger among self-described conservatives than liberals, a slight majority of whom oppose it. ...
The pipeline, proposed by Calgary-based TransCanada, has become one of the most contentious issues of Obama's presidency. Environmentalists have waged a grass-roots war against it, saying tar sands' development would worsen global warming and its delivery could risk oil spills. The oil industry and other backers say it would increase jobs and reduce U.S. dependence on unreliable foreign sources of oil. ...
The poll of n = 801 has a margin of error of +/- 4%. As I now well know (since I'm teaching stats and I know everything that is in the book!), the margin of error is determined by the formula +/- z x SQRT[(.5 x (1 - .5))/n]. With a 95% confidence level, z = 1.96 and the margin of error is 3.5%. So, where does the 4% come from? Are they just rounding up from 3.5%?