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Finding the Fourth Proportional to 386.64, 579.78 and 142.99

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Solution

The fourth proportional to 386.64, 579.78 and 142.99 is: 214.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    386.64 : 579.78 = 142.99 : x
  2. Step 2: Convert to fraction form
    386.64/579.78 = 142.99/x
  3. Step 3: Cross multiply
    386.64x = 579.78 × 142.99
  4. Step 4: Simplify right side
    386.64x = 82,902.74
  5. Step 5: Solve for x
    x = 82,902.74/386.64
  6. Step 6: Final answer
    x = 214.42

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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.