I'm having a really hard time understanding this question, can someone help me please I would really appreciate it A certain product costs $10 to make and the relationship between quantity sold q is dependent the price p

q = 1200 - 20p

The profit equation is Total Revenue (p*q) minus Production Cost (10q)

profit = pq - 10q

Using substitution, create a quadratic equation and find the price that maximizes profit.

2people are trying different phones to see which one has the better talk time. chatlong has an average of 18 hours with a standard deviation of 2 hours and talk-a-lot has an average of 20 hours with a standard deviation of 3. the two people who tested their phones both got 20 hours of use on their phones. for the z-scores i got 1 for the chatlong company and 0 for talk-a-lot. what is the percentile for each z-score?