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Finding the Fourth Proportional to 387.75, 579.57 and 318.90

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Solution

The fourth proportional to 387.75, 579.57 and 318.90 is: 476.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    387.75 : 579.57 = 318.90 : x
  2. Step 2: Convert to fraction form
    387.75/579.57 = 318.90/x
  3. Step 3: Cross multiply
    387.75x = 579.57 × 318.90
  4. Step 4: Simplify right side
    387.75x = 184,824.87
  5. Step 5: Solve for x
    x = 184,824.87/387.75
  6. Step 6: Final answer
    x = 476.66

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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.