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Finding the Fourth Proportional to 386.90, 580.49 and 143.49

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Solution

The fourth proportional to 386.90, 580.49 and 143.49 is: 215.29

Step by Step Solution

  1. Step 1: Write the proportion equation
    386.90 : 580.49 = 143.49 : x
  2. Step 2: Convert to fraction form
    386.90/580.49 = 143.49/x
  3. Step 3: Cross multiply
    386.90x = 580.49 × 143.49
  4. Step 4: Simplify right side
    386.90x = 83,293.79
  5. Step 5: Solve for x
    x = 83,293.79/386.90
  6. Step 6: Final answer
    x = 215.29

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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.