One of the many works published by the greek astronomer ptolemy (a. d ca 100-170) was optics. in this book ptolemy reports the results of refraction experiments he conducted by observing light passing from air into water. his results are as follows: angle of incidence=10 degrees, angle of refraction = 8.00 degrees, angle of incidence =20 degrees, angle of refraction =15.5 degrees. find the percentage error in the calculated index of refraction of water for each of ptolemy's measurements