9. A guitar player tunes the fundamental frequency of a guitar string to 440 Hz. What will be the fundamental frequency if she then increases the tension in the string by 15%? (13) ___ (Hz).
What will it be if, instead, she decreases the length along which the string vibrates by sliding her finger from the tuning key one-fourth of the way down the string toward the bridge at the lower end? (14) ___ (Hz)