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Finding the Fourth Proportional to 619.79, 854.70 and 398.36

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Solution

The fourth proportional to 619.79, 854.70 and 398.36 is: 549.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    619.79 : 854.70 = 398.36 : x
  2. Step 2: Convert to fraction form
    619.79/854.70 = 398.36/x
  3. Step 3: Cross multiply
    619.79x = 854.70 × 398.36
  4. Step 4: Simplify right side
    619.79x = 340,474.02
  5. Step 5: Solve for x
    x = 340,474.02/619.79
  6. Step 6: Final answer
    x = 549.34

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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.