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Finding the Fourth Proportional to 426.93, 639.93 and 280.74

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Solution

The fourth proportional to 426.93, 639.93 and 280.74 is: 420.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    426.93 : 639.93 = 280.74 : x
  2. Step 2: Convert to fraction form
    426.93/639.93 = 280.74/x
  3. Step 3: Cross multiply
    426.93x = 639.93 × 280.74
  4. Step 4: Simplify right side
    426.93x = 179,653.95
  5. Step 5: Solve for x
    x = 179,653.95/426.93
  6. Step 6: Final answer
    x = 420.80

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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.