Let's perform the calculations step by step while ensuring the correct number of significant figures and reporting the answers in scientific notation.

A.

$(2.3984 - 1.103) \div (101.1 + 203)$

1. Subtract:
   $2.3984 - 1.103 = 1.2954$ The least precise value (1.103) has 4 decimal places, so the result must have 4 decimal places: 1.2954.

2. Add:
   $101.1 + 203 = 304.1$ The least precise value (101.1) has 1 decimal place, so the result must have 1 decimal place: 304.1.

3. Divide:
   $1.2954 \div 304.1 = 0.004261$ The least significant figures in the inputs are 4 (from 1.2954) and 4 (from 304.1), so the final result must have 4 significant figures:

   Answer:
   $4.261 \times 10^{-3}$

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B.

$6.21 \times 7.908$

1. Multiply:
   $6.21 \times 7.908 = 49.11348$ The least significant figures in the inputs are 3 (from 6.21) and 4 (from 7.908), so the final result must have 3 significant figures:

   Answer:
   $4.91 \times 10^1$

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C.

$(28122 - 3923.83) \times 23.3$

1. Subtract:
   $28122 - 3923.83 = 24198.17$ The least precise value (28122) has 0 decimal places, so the result must have 0 decimal places: 24198.

2. Multiply:
   $24198 \times 23.3 = 563213.4$ The least significant figures in the inputs are 5 (from 24198) and 3 (from 23.3), so the final result must have 3 significant figures:

   Answer:
   $5.63 \times 10^5$

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Final Answers in Scientific Notation

A. $4.261 \times 10^{-3}$
B. $4.91 \times 10^1$
C. $5.63 \times 10^5$

Would you like a detailed explanation of significant figures and rounding rules?

Related Questions

1. What are the rules for determining the number of significant figures in calculations?
2. How do you convert a number into scientific notation?
3. Why is it important to consider significant figures in scientific calculations?
4. What is the difference between precision and accuracy in measurements?
5. How do addition and subtraction rules differ from multiplication and division rules for significant figures?

Tip:

Always round at the end of a multi-step calculation to avoid compounding rounding errors!