Should I round my circumference and area of a circle homework or not?

Text to World Question, c;

Predict the miles traveled in 5 hours at a rate of 189 miles in 3 hours

I have two questions. For this problem, would it be, 23x-16+4x+4+8x+17=90 or 23x-16+4x+4+8x+17=180? Also, what would "x" equal?

Simplify [ (4+11) : (12-7) ]

When Kaitlin divided a fraction by 1/2, the result was a mixed number. Was the original fraction less than or greater than 1/2? Explain your reasoning.

Round 9,170.2 to the nearest ten

A newspaper reporter wants to know how popular the hobby of bird watching is in the city. He asked people at the local bird refuge if they watched birds as a hobby. Which of the following best explains whether the reporters data is valid or not?

I am very confused on how to figure out if y = 3/4x is proportional?

Alison wants to buy a mountain bike for $339.12. If she saves $28.26 each month, in how many months will she be able to buy the bike?

At 12 o'clock the temperature was 7°C. The temperature decreased by - 20°C. What is the new temperature?

Ashleys rentals charges $27.50 per hour to rent a surfboard and a wetsuit. Darlas surf shop charges $23.25 per hour to rent a surfboard plus $17 extra for a wetsuit.