A class found a report suggesting that teenagers' foot lengths are approximately normally distributed with a mean of 23 cm and a standard deviation of 2.6 cm. They wondered if this held true at their school, so they
took a random sample of n = 9 students. The mean foot length of students in their sample was ä = 24.6 cm.
To see how likely a sample like theirs was to occur by random chance alone, the class performed a simulation.
They simulated 50 samples of n = 9 lengths from a normal population with a mean of 23 cm and standard
deviation of 2.6 cm. They recorded the mean of the lengths in each sample. Here are the sample means from
their 50 samples:

Runners run around the school's football field. the cross country coach determines that the width of the field is seventy yards shorter than the length. part a write an expression that represents the perimeter of the football field. let x represent the length of the football field. include parentheses in your expression. next, write an equivalent expression that does not include parentheses. what property or properties did you use to simplify? explain. part b the cross country coach later determines that the length of the football field is 120 yards. all students must run five laps. using your answer from part a, determine the actual number of yards that each athlete must run in the tryouts. in order to make the team, students must complete the laps in 6 minutes. how quickly must they run each lap?