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Finding the Fourth Proportional to 512.78, 707.61 and 279.86

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Solution

The fourth proportional to 512.78, 707.61 and 279.86 is: 386.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    512.78 : 707.61 = 279.86 : x
  2. Step 2: Convert to fraction form
    512.78/707.61 = 279.86/x
  3. Step 3: Cross multiply
    512.78x = 707.61 × 279.86
  4. Step 4: Simplify right side
    512.78x = 198,031.73
  5. Step 5: Solve for x
    x = 198,031.73/512.78
  6. Step 6: Final answer
    x = 386.19

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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.