Innumeracy in the news

I was half asleep while watching the news this morning, but halfway through my first cup of coffee this story caught my attention:

Customers speak out about Duke Energy rate increase

"Raleigh, N.C. — Duke Energy customers voiced their concerns on Thursday night about a planned 13.5 percent rate increase.

"Under the plan, people with an average monthly bill of $100 a month would go up about $18."

I hate to pick on my friends at WRAL, but how did that get on the air?

WNCN says the increase is 12.6% -- and their math works out:

"The utility wants a 12.6 percent hike, which would be an additional $150 a year for a household that currently pays about $100 a month."

WTVD also says the rate hike is 12.6%, and claims that it's "about $11 per month." But they don't mention a base rate. If the average bill is around $87, then that works out.

Is the proposed rate increase 12.6%, or 13.5%? Is the average bill going up $11 per month, $150 per year, or $18 per month? Is $18 = to 13.5% of $100?