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Finding the Fourth Proportional to 512.75, 768.51 and 390.65

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Solution

The fourth proportional to 512.75, 768.51 and 390.65 is: 585.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    512.75 : 768.51 = 390.65 : x
  2. Step 2: Convert to fraction form
    512.75/768.51 = 390.65/x
  3. Step 3: Cross multiply
    512.75x = 768.51 × 390.65
  4. Step 4: Simplify right side
    512.75x = 300,214.59
  5. Step 5: Solve for x
    x = 300,214.59/512.75
  6. Step 6: Final answer
    x = 585.50

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Similar ratio
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1.5x scale

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.