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Finding the Fourth Proportional to 619.76, 854.53 and 398.72

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Solution

The fourth proportional to 619.76, 854.53 and 398.72 is: 549.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    619.76 : 854.53 = 398.72 : x
  2. Step 2: Convert to fraction form
    619.76/854.53 = 398.72/x
  3. Step 3: Cross multiply
    619.76x = 854.53 × 398.72
  4. Step 4: Simplify right side
    619.76x = 340,712.93
  5. Step 5: Solve for x
    x = 340,712.93/619.76
  6. Step 6: Final answer
    x = 549.75

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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.