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Finding the Fourth Proportional to 387.91, 579.43 and 329.86

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Solution

The fourth proportional to 387.91, 579.43 and 329.86 is: 492.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    387.91 : 579.43 = 329.86 : x
  2. Step 2: Convert to fraction form
    387.91/579.43 = 329.86/x
  3. Step 3: Cross multiply
    387.91x = 579.43 × 329.86
  4. Step 4: Simplify right side
    387.91x = 191,130.78
  5. Step 5: Solve for x
    x = 191,130.78/387.91
  6. Step 6: Final answer
    x = 492.72

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.