2010 House · MI-7
EPIC-MRA · fieldwork ended 2010-10-16 (17 days before the election) · 400 respondents · Live Phone
The poll said
Democrat 45% · Republican 39%
D+6.0
The certified result
Democrat 45.38% · Republican 50.16%
R+4.8
The arithmetic
- Poll margin = 45 − 39 = 6.00
- Actual margin = 45.377 − 50.155 = -4.778
- Signed miss = 6.00 − (-4.778) = 10.778
- Absolute miss = |10.778| = 10.778
The poll overstated the Democrat by 10.8 points and had the wrong leader.
Where these numbers come from
Poll and result: 538 raw_polls.csv. Poll ID 51862, race ID 4665 (538 database).