Quadrilateral abcd is inscribed in this circle.
what is the measure of angle a?

How do you answer this question? (step by step)

Express the following as a function of a single angle, cos(60) cos(-20) - sin(60) sin(-20)

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.