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Finding the Fourth Proportional to 385.57, 578.34 and 129.07

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Solution

The fourth proportional to 385.57, 578.34 and 129.07 is: 193.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    385.57 : 578.34 = 129.07 : x
  2. Step 2: Convert to fraction form
    385.57/578.34 = 129.07/x
  3. Step 3: Cross multiply
    385.57x = 578.34 × 129.07
  4. Step 4: Simplify right side
    385.57x = 74,646.34
  5. Step 5: Solve for x
    x = 74,646.34/385.57
  6. Step 6: Final answer
    x = 193.60

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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.