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Finding the Fourth Proportional to 490.40, 676.88 and 387.36

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Solution

The fourth proportional to 490.40, 676.88 and 387.36 is: 534.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    490.40 : 676.88 = 387.36 : x
  2. Step 2: Convert to fraction form
    490.40/676.88 = 387.36/x
  3. Step 3: Cross multiply
    490.40x = 676.88 × 387.36
  4. Step 4: Simplify right side
    490.40x = 262,196.24
  5. Step 5: Solve for x
    x = 262,196.24/490.40
  6. Step 6: Final answer
    x = 534.66

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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.