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Finding the Fourth Proportional to 639.04, 881.40 and 406

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Solution

The fourth proportional to 639.04, 881.40 and 406 is: 559.98

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.04 : 881.40 = 406 : x
  2. Step 2: Convert to fraction form
    639.04/881.40 = 406/x
  3. Step 3: Cross multiply
    639.04x = 881.40 × 406
  4. Step 4: Simplify right side
    639.04x = 357,848.40
  5. Step 5: Solve for x
    x = 357,848.40/639.04
  6. Step 6: Final answer
    x = 559.98

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.