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Finding the Fourth Proportional to 509.69, 703.26 and 391.80

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Solution

The fourth proportional to 509.69, 703.26 and 391.80 is: 540.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    509.69 : 703.26 = 391.80 : x
  2. Step 2: Convert to fraction form
    509.69/703.26 = 391.80/x
  3. Step 3: Cross multiply
    509.69x = 703.26 × 391.80
  4. Step 4: Simplify right side
    509.69x = 275,539.91
  5. Step 5: Solve for x
    x = 275,539.91/509.69
  6. Step 6: Final answer
    x = 540.60

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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.