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Finding the Fourth Proportional to 386.87, 580.41 and 143.42

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Solution

The fourth proportional to 386.87, 580.41 and 143.42 is: 215.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    386.87 : 580.41 = 143.42 : x
  2. Step 2: Convert to fraction form
    386.87/580.41 = 143.42/x
  3. Step 3: Cross multiply
    386.87x = 580.41 × 143.42
  4. Step 4: Simplify right side
    386.87x = 83,239.50
  5. Step 5: Solve for x
    x = 83,239.50/386.87
  6. Step 6: Final answer
    x = 215.16

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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.