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Finding the Fourth Proportional to 687.98, 949.33 and 389.20

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Solution

The fourth proportional to 687.98, 949.33 and 389.20 is: 537.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    687.98 : 949.33 = 389.20 : x
  2. Step 2: Convert to fraction form
    687.98/949.33 = 389.20/x
  3. Step 3: Cross multiply
    687.98x = 949.33 × 389.20
  4. Step 4: Simplify right side
    687.98x = 369,479.24
  5. Step 5: Solve for x
    x = 369,479.24/687.98
  6. Step 6: Final answer
    x = 537.05

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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.