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Finding the Fourth Proportional to 103.05, 155.09 and 77.50

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Solution

The fourth proportional to 103.05, 155.09 and 77.50 is: 116.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    103.05 : 155.09 = 77.50 : x
  2. Step 2: Convert to fraction form
    103.05/155.09 = 77.50/x
  3. Step 3: Cross multiply
    103.05x = 155.09 × 77.50
  4. Step 4: Simplify right side
    103.05x = 12,019.28
  5. Step 5: Solve for x
    x = 12,019.28/103.05
  6. Step 6: Final answer
    x = 116.64

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.