What is the quadratic regression equation for the data set?

yˆ=−0.004x2+0.415x−0.546

yˆ=−0.004x2−0.415x−0.546

yˆ=0.004x2+0.415x+0.546

yˆ=−0.004x2−0.415x+0.546
x y
50 10
30 11
11 5
35 9
50 12
20 3
90 7

Atest consists of 10 multiple choice questions, each with 5 possible answers, one of which is correct. to pass the test a student must get 60% or better on the test. if a student randomly guesses, what is the probability that the student will pass the test?