How to Change from Frequency Domain to Time Domain with IFFT & FFT

I have the following data. Note the odd number of data points since I'm not sure if this affects the script or not. It is acceleration data in a frequency domain. I need to convert it to a time domain and then back, which will thereby prove the conversion worked properly. As I understand, I need the IFFT and FFT commands, but I don't understand them well enough to construct the script properly. Can anyone help?

I'm new, so please provide answers in simple terms with clear explanation, since I'm trying to learn and get a better understanding.

Thanks, M Ridzon

%Define frequency vector
Freq=[6,6.3,6.6,6.9,7.2,7.329,7.3544,7.3892,9.0312,9.3,9.6,9.9,10.2,10.5,10.8,11.1,11.4,11.7,12,12.3,12.6,12.9,13.2,13.5,13.8];

%Define acceleration vector
Accel=[2.3448,2.6998,3.1221,3.5948,4.1496,4.3716,4.3716,4.3911,4.3911,4.1289,3.6627,3.1965,2.84,2.5385,2.2369,2.0053,1.9136,1.8115,1.6938,1.5942,1.5466,1.4989,1.449,1.3986,1.3504];

[Matthew]

I also just realized Matlab has the 'fourier' and 'ifourier' commands available. Perhaps these would be more suitable?

Please help! Thanks in advance!

M Ridzon