A survey result shows that cell phone usage among teenagers rose from 63% in 2006 to 71% in 2008. Of the following choices, which statement about cell phone use among teenagers is true?
a. Cell phone usage rose by 11.2 percentage points.
b. Cell phone usage rose by 12.7 percentage points.
c. Cell phone usage rose by 12.7%.
d. Cell phone usage rose by 8%.

Solve for x, y, and z. show all steps.

Mexico city, mexico, is the world's second largest metropolis and is also one of its fastest-growing cities with a projected growth rate of 3.2% per year. its population in 1991 was 20,899,000 people. use the formula p = 20.899e0.032t to predict its population p in millions with t equal to the number of years after 1991. what is the predicted population to the nearest thousand of mexico city for the year 2010?

Guys i really need or i have to stay late up night