No, in hexadecimal constants the exponent is still in decimal and is a power of two. Thus this example is 30/2 not 30/16. (Anyway 0.9375 is 15/16; not sure how you got that.)

Thus the example is correct.

From the spec:
A hexadecimal floating-point literal consists of a 0x or 0X prefix, an integer part (hexadecimal digits), a radix point, a fractional part (hexadecimal digits), and an exponent part (p or P followed by an optional sign and decimal digits). One of the integer part or the fractional part may be elided; the radix point may be elided as well, but the exponent part is required. (This syntax matches the one given in IEEE 754-2008 §5.12.3.) An exponent value exp scales the mantissa (integer and fractional part) by 2exp.

Thank you robpike