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Finding the Fourth Proportional to 712.40, 983.10 and 401.90

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Solution

The fourth proportional to 712.40, 983.10 and 401.90 is: 554.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    712.40 : 983.10 = 401.90 : x
  2. Step 2: Convert to fraction form
    712.40/983.10 = 401.90/x
  3. Step 3: Cross multiply
    712.40x = 983.10 × 401.90
  4. Step 4: Simplify right side
    712.40x = 395,107.89
  5. Step 5: Solve for x
    x = 395,107.89/712.40
  6. Step 6: Final answer
    x = 554.62

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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.