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Finding the Fourth Proportional to 143.20, 214.80 and 71.20

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Solution

The fourth proportional to 143.20, 214.80 and 71.20 is: 106.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    143.20 : 214.80 = 71.20 : x
  2. Step 2: Convert to fraction form
    143.20/214.80 = 71.20/x
  3. Step 3: Cross multiply
    143.20x = 214.80 × 71.20
  4. Step 4: Simplify right side
    143.20x = 15,293.76
  5. Step 5: Solve for x
    x = 15,293.76/143.20
  6. Step 6: Final answer
    x = 106.80

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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.