So basically to change this to a decimal, you want to first change the denominator to 100. You can do this by multiplying the fraction by 4/4, which is still 1, but just with a denominator of 4.
19/25 * 4/4 = (19*4) / (25 * 4) = 76 / 100
So now you can just convert this to a decimal, and say 0.76.