Is this a valid way to initalize an NSArray with float objects?
NSArray *fatArray = [NSArray arrayWithObjects: [NSNumber numberWithFloat:6.9]
going off on a slight tangent, if all you want to do is store an array of floats and don't really need the added functionality of an NSArray or NSNumber, then you should also consider just a standard C array:
float fatArray[] = {6.6, 6.9, 4.7, 6.9};