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Finding the Fourth Proportional to 780.78, 1,077.48 and 426.70

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Solution

The fourth proportional to 780.78, 1,077.48 and 426.70 is: 588.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    780.78 : 1,077.48 = 426.70 : x
  2. Step 2: Convert to fraction form
    780.78/1,077.48 = 426.70/x
  3. Step 3: Cross multiply
    780.78x = 1,077.48 × 426.70
  4. Step 4: Simplify right side
    780.78x = 459,760.72
  5. Step 5: Solve for x
    x = 459,760.72/780.78
  6. Step 6: Final answer
    x = 588.85

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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.