Multiply four decimals accurately Evaluate 5 × 0.25 × 6.301 × 0.00394.

Introduction / Context:When multiple decimals are multiplied, an efficient approach is to combine simple pairs first (like 5 × 0.25), then proceed stepwise, keeping careful track of decimal places to avoid rounding errors.

Given Data / Assumptions:

• Compute P = 5 × 0.25 × 6.301 × 0.00394.
• Report the exact product to all shown decimal places.

Concept / Approach:First, simplify easy multipliers: 5 × 0.25 = 1.25. Then multiply by 6.301 and finally by 0.00394. Alternatively, convert 0.00394 to 394/100000 to simplify decimal placement.

Step-by-Step Solution:5 × 0.25 = 1.25.1.25 × 6.301 = 7.87625.Now 7.87625 × 0.00394 = 7.87625 × (394/100000).7.87625 × 394 = 7.87625 × (400 − 6) = 3150.5 − 47.2575 = 3103.2425.Divide by 100000 ⇒ 0.031032425.

Verification / Alternative check:Use a calculator to confirm 0.031032425 exactly; the trailing zero version 0.0310324250 matches formatting in options.

Why Other Options Are Wrong:0.0310324220 and 0.0310324210 truncate or miscompute the middle step slightly; “None of these” is incorrect since the exact value is present.

Common Pitfalls:Not simplifying 5 × 0.25; mishandling 0.00394; misplacing the decimal after large-integer multiplication.

Final Answer:0.0310324250