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Finding the Fourth Proportional to 1,292.78, 1,939.35 and 426.89

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Solution

The fourth proportional to 1,292.78, 1,939.35 and 426.89 is: 640.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,292.78 : 1,939.35 = 426.89 : x
  2. Step 2: Convert to fraction form
    1,292.78/1,939.35 = 426.89/x
  3. Step 3: Cross multiply
    1,292.78x = 1,939.35 × 426.89
  4. Step 4: Simplify right side
    1,292.78x = 827,889.12
  5. Step 5: Solve for x
    x = 827,889.12/1,292.78
  6. Step 6: Final answer
    x = 640.39

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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.