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Finding the Fourth Proportional to 385.79, 581.31 and 318.78

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Solution

The fourth proportional to 385.79, 581.31 and 318.78 is: 480.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    385.79 : 581.31 = 318.78 : x
  2. Step 2: Convert to fraction form
    385.79/581.31 = 318.78/x
  3. Step 3: Cross multiply
    385.79x = 581.31 × 318.78
  4. Step 4: Simplify right side
    385.79x = 185,310.00
  5. Step 5: Solve for x
    x = 185,310.00/385.79
  6. Step 6: Final answer
    x = 480.35

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.