Pls help :(

If a and b are the measures of two first quadrant angles and sin a = 4/9 and sin b = 2/5 find sin(a+b).

Asimple random sample of size nequals14 is drawn from a population that is normally distributed. the sample mean is found to be x overbar equals 70 and the sample standard deviation is found to be sequals13. construct a 90% confidence interval about the population mean

Parks is wearing several rubber bracelets one third of the bracelets are tie dye 1/6 are blue and 1/3 of the remainder are camouflage if park swears to camouflage bracelets how many bracelets does he have on