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Finding the Fourth Proportional to 386.70, 579.80 and 143.12

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Solution

The fourth proportional to 386.70, 579.80 and 143.12 is: 214.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    386.70 : 579.80 = 143.12 : x
  2. Step 2: Convert to fraction form
    386.70/579.80 = 143.12/x
  3. Step 3: Cross multiply
    386.70x = 579.80 × 143.12
  4. Step 4: Simplify right side
    386.70x = 82,980.98
  5. Step 5: Solve for x
    x = 82,980.98/386.70
  6. Step 6: Final answer
    x = 214.59

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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.