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Finding the Fourth Proportional to 712.90, 983.74 and 398.14

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Solution

The fourth proportional to 712.90, 983.74 and 398.14 is: 549.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    712.90 : 983.74 = 398.14 : x
  2. Step 2: Convert to fraction form
    712.90/983.74 = 398.14/x
  3. Step 3: Cross multiply
    712.90x = 983.74 × 398.14
  4. Step 4: Simplify right side
    712.90x = 391,666.32
  5. Step 5: Solve for x
    x = 391,666.32/712.90
  6. Step 6: Final answer
    x = 549.40

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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.