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Finding the Fourth Proportional to 386.78, 579.79 and 143.24

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Solution

The fourth proportional to 386.78, 579.79 and 143.24 is: 214.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    386.78 : 579.79 = 143.24 : x
  2. Step 2: Convert to fraction form
    386.78/579.79 = 143.24/x
  3. Step 3: Cross multiply
    386.78x = 579.79 × 143.24
  4. Step 4: Simplify right side
    386.78x = 83,046.40
  5. Step 5: Solve for x
    x = 83,046.40/386.78
  6. Step 6: Final answer
    x = 214.72

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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.