The graph below represents the height h in feet of a ball t seconds after it's thrown. The path of the ball is represented by the equation h = -t^2 + 8t. What is the maximum height of the ball?

What interval is the ball increasing in its height?

When does the ball hit the ground?

At the beginning of the day, stock xyz opened at $6.12. at the end of the day, it closed at $6.88. what is the rate of change of stock xyz? a. 1.17% b. 11.0% c. 12.4% d. 81.5%

What is the number 321,000,000 in scientific notation? also what is the number? ?

The management of a supermarket wants to adopt a new promotional policy of giving a free gift to every customer who spends more than a certain amount per visit at this supermarket. the expectation of the management is that after this promotional policy is advertised, the expenditures for all customers at this supermarket will be normally distributed with a mean of $95 and a standard deviation of $20. if the management wants to give free gifts to at most 10% of the customers, what should the amount be above which a customer would receive a free gift?