Please help me with these 2 questions!! Will mark Brainliest :)

Identify a1 and r for the geometric sequence an= -256(-1/4) n-1

I’m really confused and need to learn this

Aclothing designer is selecting models to walk the runway for her fashion show. the clothes she designed require each model’s height to be no more than y inches from 5 feet 10 inches, or 70 inches. which graph could be used to determine the possible variance levels that would result in an acceptable height, x?