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Finding the Fourth Proportional to 402.72, 555.59 and 309.30

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Solution

The fourth proportional to 402.72, 555.59 and 309.30 is: 426.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    402.72 : 555.59 = 309.30 : x
  2. Step 2: Convert to fraction form
    402.72/555.59 = 309.30/x
  3. Step 3: Cross multiply
    402.72x = 555.59 × 309.30
  4. Step 4: Simplify right side
    402.72x = 171,842.44
  5. Step 5: Solve for x
    x = 171,842.44/402.72
  6. Step 6: Final answer
    x = 426.70

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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.