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Finding the Fourth Proportional to 129.75, 179.05 and 74.50

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Solution

The fourth proportional to 129.75, 179.05 and 74.50 is: 102.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    129.75 : 179.05 = 74.50 : x
  2. Step 2: Convert to fraction form
    129.75/179.05 = 74.50/x
  3. Step 3: Cross multiply
    129.75x = 179.05 × 74.50
  4. Step 4: Simplify right side
    129.75x = 13,338.33
  5. Step 5: Solve for x
    x = 13,338.33/129.75
  6. Step 6: Final answer
    x = 102.80

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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.