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Finding the Fourth Proportional to 729.61, 1,006.87 and 398.05

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Solution

The fourth proportional to 729.61, 1,006.87 and 398.05 is: 549.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    729.61 : 1,006.87 = 398.05 : x
  2. Step 2: Convert to fraction form
    729.61/1,006.87 = 398.05/x
  3. Step 3: Cross multiply
    729.61x = 1,006.87 × 398.05
  4. Step 4: Simplify right side
    729.61x = 400,779.57
  5. Step 5: Solve for x
    x = 400,779.57/729.61
  6. Step 6: Final answer
    x = 549.31

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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.