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Finding the Fourth Proportional to 143.80, 215.54 and 86.10

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Solution

The fourth proportional to 143.80, 215.54 and 86.10 is: 129.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    143.80 : 215.54 = 86.10 : x
  2. Step 2: Convert to fraction form
    143.80/215.54 = 86.10/x
  3. Step 3: Cross multiply
    143.80x = 215.54 × 86.10
  4. Step 4: Simplify right side
    143.80x = 18,557.99
  5. Step 5: Solve for x
    x = 18,557.99/143.80
  6. Step 6: Final answer
    x = 129.05

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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.