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Finding the Fourth Proportional to 124.30, 171.45 and 86.89

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Solution

The fourth proportional to 124.30, 171.45 and 86.89 is: 119.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    124.30 : 171.45 = 86.89 : x
  2. Step 2: Convert to fraction form
    124.30/171.45 = 86.89/x
  3. Step 3: Cross multiply
    124.30x = 171.45 × 86.89
  4. Step 4: Simplify right side
    124.30x = 14,897.18
  5. Step 5: Solve for x
    x = 14,897.18/124.30
  6. Step 6: Final answer
    x = 119.85

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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.