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Finding the Fourth Proportional to 402.50, 555.70 and 309.07

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Solution

The fourth proportional to 402.50, 555.70 and 309.07 is: 426.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    402.50 : 555.70 = 309.07 : x
  2. Step 2: Convert to fraction form
    402.50/555.70 = 309.07/x
  3. Step 3: Cross multiply
    402.50x = 555.70 × 309.07
  4. Step 4: Simplify right side
    402.50x = 171,749.78
  5. Step 5: Solve for x
    x = 171,749.78/402.50
  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.