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Finding the Fourth Proportional to 647.40, 892.42 and 507.21

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Solution

The fourth proportional to 647.40, 892.42 and 507.21 is: 699.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    647.40 : 892.42 = 507.21 : x
  2. Step 2: Convert to fraction form
    647.40/892.42 = 507.21/x
  3. Step 3: Cross multiply
    647.40x = 892.42 × 507.21
  4. Step 4: Simplify right side
    647.40x = 452,644.35
  5. Step 5: Solve for x
    x = 452,644.35/647.40
  6. Step 6: Final answer
    x = 699.17

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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.