Which relationship is always true for the angles r, x, y, and z of triangle ABC? a.
x + z = y

b.
180 degrees − x = r

c.
x + y + z = 180 degrees

d.
x + y + z = 90 degrees

According to a study conducted in 2015, 18% of shoppers said that they prefer to buy generic instead of name-brand products. suppose that in a recent sample of 1500 shoppers, 315 stated that they prefer to buy generic instead of name-brand products. at a 5% significance level, can you conclude that the proportion of all shoppers who currently prefer to buy generic instead of name-brand products is higher than .18? use both the p-value and the critical-value approaches.