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Finding the Fourth Proportional to 103.08, 153.87 and 85.80

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Solution

The fourth proportional to 103.08, 153.87 and 85.80 is: 128.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    103.08 : 153.87 = 85.80 : x
  2. Step 2: Convert to fraction form
    103.08/153.87 = 85.80/x
  3. Step 3: Cross multiply
    103.08x = 153.87 × 85.80
  4. Step 4: Simplify right side
    103.08x = 13,202.05
  5. Step 5: Solve for x
    x = 13,202.05/103.08
  6. Step 6: Final answer
    x = 128.08

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.