23) Boxes of bouncy balls with 500 balls are sold to stores for $75.00. One store sells them to customers for 35 cents each. What is the difference between the unit buying price and the selling price? Write each scale as a ratio in lowest terms:
24) 10cm represents 20km
25) 1cm represents 400km
26) 1cm represents 5mm

I’m confused on how to work the pie charts

Monitors manufactured by tsi electronics have life spans that have a normal distribution with a standard deviation of 1800 hours and a mean life span of 20,000 hours. if a monitor is selected at random, find the probability that the life span of the monitor will be more than 17,659 hours. round your answer to four decimal places.

(10. in the figure, a aabc is drawn tocircumscribe a circle of radius 3 cm ,such thatthe segments bd and dc are respectively oflength 6 cm and 9 cm. find the length ofsides ab and ac.