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Finding the Fourth Proportional to 618.40, 851.78 and 431.55

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Solution

The fourth proportional to 618.40, 851.78 and 431.55 is: 594.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    618.40 : 851.78 = 431.55 : x
  2. Step 2: Convert to fraction form
    618.40/851.78 = 431.55/x
  3. Step 3: Cross multiply
    618.40x = 851.78 × 431.55
  4. Step 4: Simplify right side
    618.40x = 367,585.66
  5. Step 5: Solve for x
    x = 367,585.66/618.40
  6. Step 6: Final answer
    x = 594.41

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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.