If a states sales tax is 7 percent, what is the amount of sales tax that would be paid on a bill of $8.50

For a particular set of atmospheric conditions, the function y z 349 models the frequency, y, in waves per second, of sound waves with a wavelength of y meters a note played on a guitar has a frequency of 440 waves per second. to the nearest centimeter what is the wavelength of the note? centimeters