Bias matching? Need help pls

What is the slope of a line that is perpendicular to y = 3x + 1

Compare these two waves: the blue and orange waves have the same pitch, but the blue wave is louder. the blue and orange waves have the same volume, but the blue wave has a higher pitch. the orange wave has a higher pitch, but the blue wave is louder. the blue wave has a higher pitch, but the orange wave is louder.

What is the value with a place of tenths in 907.456 1) 0 2) 6 3) 4 4) 5