Need help please you only have to answer the last two

Acompany is making new soccer uniforms for a team. the company uses 2.5 yards of fabric for each shirt. the company uses 82.5 yards of fabric to make shirts and shorts for 15 players. the equation and solution below represents the situation. 15(2.5+x)=82.5; x=3 what does the solution, x=3, represent?

Given the following sampling distribution of one mean with a sample size 49, from a normally distributed population,find the population standard deviation, o.79828588912497

Xto the second power plus 14x plus 48. what are the factors? we are doing factoring trinomials with a=1