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Finding the Fourth Proportional to 687.88, 949.26 and 389.12

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Solution

The fourth proportional to 687.88, 949.26 and 389.12 is: 536.98

Step by Step Solution

  1. Step 1: Write the proportion equation
    687.88 : 949.26 = 389.12 : x
  2. Step 2: Convert to fraction form
    687.88/949.26 = 389.12/x
  3. Step 3: Cross multiply
    687.88x = 949.26 × 389.12
  4. Step 4: Simplify right side
    687.88x = 369,372.15
  5. Step 5: Solve for x
    x = 369,372.15/687.88
  6. Step 6: Final answer
    x = 536.98

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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.