Melanie spent four hours babysitting. She charges $16 up front and then an additional charge per hour. The total amount she earned can be represented by the expression $4x + $16. What expression represents the amount she earns each hour? Please give me the expression.. if u just say i don't know i will report ;)

Describe in detail how you would construct a 95% confidence interval for a set of 30 data points whose mean is 20 and population standard deviation is 3. be sure to show that you know the formula and how to plug into it. also, clearly state the margin of error.

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?

Find the area of the regular hexagon if a side is 20 cm.