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Finding the Fourth Proportional to 512.88, 707.79 and 280

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Solution

The fourth proportional to 512.88, 707.79 and 280 is: 386.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    512.88 : 707.79 = 280 : x
  2. Step 2: Convert to fraction form
    512.88/707.79 = 280/x
  3. Step 3: Cross multiply
    512.88x = 707.79 × 280
  4. Step 4: Simplify right side
    512.88x = 198,181.20
  5. Step 5: Solve for x
    x = 198,181.20/512.88
  6. Step 6: Final answer
    x = 386.41

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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.