HELP SOMEONE
Find all complex numbers $z$ such that $z^4 = -4.$

The diameter of a ball is 8 in. what is the volume of the ball? use 3.14 for pi. enter your answer as a decimal in the box. round only your final answer to the nearest hundredth.

Acompany wants to reduce the dimensions of its logo by one fourth to use on business cards. if the area of the original logo is 4 square inches, what is the area of the logo that will be used on the business cards?

An energy drink company claims that its product increases students' memory levels. to support its claims, the company issues advertisements claiming that 8 out of 10 people (chosen randomly from across the country) who tried their product reported improved memory. the missing component in this study is a .