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Finding the Fourth Proportional to 712.78, 1,069.32 and 279.94

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Solution

The fourth proportional to 712.78, 1,069.32 and 279.94 is: 419.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    712.78 : 1,069.32 = 279.94 : x
  2. Step 2: Convert to fraction form
    712.78/1,069.32 = 279.94/x
  3. Step 3: Cross multiply
    712.78x = 1,069.32 × 279.94
  4. Step 4: Simplify right side
    712.78x = 299,345.44
  5. Step 5: Solve for x
    x = 299,345.44/712.78
  6. Step 6: Final answer
    x = 419.97

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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.