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Finding the Fourth Proportional to 439.99, 657.13 and 398.78

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Solution

The fourth proportional to 439.99, 657.13 and 398.78 is: 595.57

Step by Step Solution

  1. Step 1: Write the proportion equation
    439.99 : 657.13 = 398.78 : x
  2. Step 2: Convert to fraction form
    439.99/657.13 = 398.78/x
  3. Step 3: Cross multiply
    439.99x = 657.13 × 398.78
  4. Step 4: Simplify right side
    439.99x = 262,045.02
  5. Step 5: Solve for x
    x = 262,045.02/439.99
  6. Step 6: Final answer
    x = 595.57

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.