Final answer:
The reciprocal of a number ending in 2.5 starts with a 4. For significant figures, a value like 2,085.5688 is rounded to five significant figures as 2,085.6, rounding up due to the tenths digit being 5.
Step-by-step explanation:
The question appears to be asking for an explanation of how to find the reciprocal of a decimal and how to handle significant figures when rounding numbers from a calculator or a table of values. For a number ending in 2.5, such as 2.5 itself, the starting point for its reciprocal would begin with a 4, since the reciprocal of 2.5 is 0.4 (ignoring where the decimal point is located). If we speak of the reciprocal of 4/11, in decimal form it would be approximately 0.363636 recurring, which starts with a 3 not a 4.
Additionally, significant figures play a role when rounding calculator answers. When a calculator provides a precise value such as 2,085.5688, and we need to round it to five significant figures, we follow the rule of rounding up or down based on the first digit to be dropped. In this case, the digit in the tenths place is 5, which prompts us to round up to 2,085.6.