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Finding the Fourth Proportional to 385.88, 578.84 and 129.36

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Solution

The fourth proportional to 385.88, 578.84 and 129.36 is: 194.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    385.88 : 578.84 = 129.36 : x
  2. Step 2: Convert to fraction form
    385.88/578.84 = 129.36/x
  3. Step 3: Cross multiply
    385.88x = 578.84 × 129.36
  4. Step 4: Simplify right side
    385.88x = 74,878.74
  5. Step 5: Solve for x
    x = 74,878.74/385.88
  6. Step 6: Final answer
    x = 194.05

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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.