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Finding the Fourth Proportional to 124.40, 171.65 and 80.72

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Solution

The fourth proportional to 124.40, 171.65 and 80.72 is: 111.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    124.40 : 171.65 = 80.72 : x
  2. Step 2: Convert to fraction form
    124.40/171.65 = 80.72/x
  3. Step 3: Cross multiply
    124.40x = 171.65 × 80.72
  4. Step 4: Simplify right side
    124.40x = 13,855.18
  5. Step 5: Solve for x
    x = 13,855.18/124.40
  6. Step 6: Final answer
    x = 111.38

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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.