Only b

My answer is incorrect the correct answer is 430.0Hz, please write your explanation(process detail) why the answer is 430.0Hz and write why my answer is wrong.

I attach the image and write my process of explanation.

My solution:

1. One way to tune a piano is to strike a tuning fork (which emits only one specific frequency), then immediately strike the piano key for the frequency being sounded by the fork, and listen for beats. If the frequency of an out-of-tune A4 string is 420.0 Hz, and a tuner strikes an A4 tuning fork (frequency 440.0 Hz), a. ...what beat frequency will the tuner hear? JB = ffork - fax FB = (440. OH/g) - (020. 0 Hz) = 20. 017 20. of2 b. ...and what frequency note will the tuner hear? Since the tuned A, string must have the same frequency as that of the tuning fork the frequency note of the An String will be fnote: 440.OHz b) fnote = 440 0Hzb. .. .and what frequency note will the tuner hear? decimal 4 40.0 Hz + 420.0 A7 860. 0 H z note 2 2 2 + = 430. 0 H2