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Finding the Fourth Proportional to 124.05, 171.20 and 87.20

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Solution

The fourth proportional to 124.05, 171.20 and 87.20 is: 120.33

Step by Step Solution

  1. Step 1: Write the proportion equation
    124.05 : 171.20 = 87.20 : x
  2. Step 2: Convert to fraction form
    124.05/171.20 = 87.20/x
  3. Step 3: Cross multiply
    124.05x = 171.20 × 87.20
  4. Step 4: Simplify right side
    124.05x = 14,927.35
  5. Step 5: Solve for x
    x = 14,927.35/124.05
  6. Step 6: Final answer
    x = 120.33

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.