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Finding the Fourth Proportional to 612.65, 845.69 and 391.79

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Solution

The fourth proportional to 612.65, 845.69 and 391.79 is: 540.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    612.65 : 845.69 = 391.79 : x
  2. Step 2: Convert to fraction form
    612.65/845.69 = 391.79/x
  3. Step 3: Cross multiply
    612.65x = 845.69 × 391.79
  4. Step 4: Simplify right side
    612.65x = 331,326.70
  5. Step 5: Solve for x
    x = 331,326.70/612.65
  6. Step 6: Final answer
    x = 540.81

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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.