What should be the following

Convert to 15°C of HSD Specific gravity 0.834 to

To convert specific gravity to 15°C, you can use the following formula:

SG15 = SGobserved / (1 + (0.0008 * (Tobserved - 15)))

Where:
SG15 = Specific gravity at 15°C
SGobserved = Specific gravity at observed temperature (0.834 in this case)
Tobserved = Observed temperature (assumed to be 20°C)

Plug in the values:

SG15 = 0.834 / (1 + (0.0008 * (20 - 15)))
SG15 = 0.832

Therefore, the specific gravity of HSD at 15°C would be 0.832.