Final answer:
To convert the mixed number 4+3 2/5 to decimal form, convert the fraction 2/5 to 0.4, add it to the whole number 3 to get 3.4, then add this to the whole number 4 to obtain 7.4.
Step-by-step explanation:
To convert the mixed number 4+3 2/5 to decimal form, you start by converting the fractional part to a decimal. The fractional part is 3 2/5, which means 3 plus 2 fifths. To convert 2/5 to a decimal, you divide 2 by 5 which gives you 0.4. Now, you add the whole number part, which is 3, to 0.4 to get 3.4. Finally, add this to the other whole number 4 to get 7.4 as the decimal form of 4+3 2/5.
Regarding significant figures, if you were to round a number like 2,085.5688 to five significant figures, you would look at the sixth figure to decide whether to round up or down. Since it's a number greater than 5, you would round the number to 2,085.6.