What does +/- 5 mean? Discuss the concept of margin of error in detail.

Question

kittyjosh · Answer

A margin of error is an amount that is allowed in a case of miscalculation. A margin of error is a surveys amount of uncertainty.

 A +/-5 means that the sampling can be off by about 5%.

Lets say I took a poll on who people supported for president, and I got these totals...

Barack Obama - 50%
Willard Mitt Romney - 40%
Gary Johnson - 9%
Jill Stein - 1%

The +/-5 margin of error means that my totals may be off by 5% in either direction, so instead of 50% of people supporting Obama, if we polled EVERY human in the United States, that total might be closer to 45%, or 55%.

happykiddo · Answer

Wow, Thanks! 
I rarely get a response in the history section and the examples really help
Thanks once again : )

kittyjosh · Answer

As always, you are welcome. :-))