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Finding the Fourth Proportional to 512.30, 767.84 and 390.80

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Solution

The fourth proportional to 512.30, 767.84 and 390.80 is: 585.73

Step by Step Solution

  1. Step 1: Write the proportion equation
    512.30 : 767.84 = 390.80 : x
  2. Step 2: Convert to fraction form
    512.30/767.84 = 390.80/x
  3. Step 3: Cross multiply
    512.30x = 767.84 × 390.80
  4. Step 4: Simplify right side
    512.30x = 300,071.87
  5. Step 5: Solve for x
    x = 300,071.87/512.30
  6. Step 6: Final answer
    x = 585.73

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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.