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Finding the Fourth Proportional to 103.08, 155.19 and 85.32

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Solution

The fourth proportional to 103.08, 155.19 and 85.32 is: 128.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    103.08 : 155.19 = 85.32 : x
  2. Step 2: Convert to fraction form
    103.08/155.19 = 85.32/x
  3. Step 3: Cross multiply
    103.08x = 155.19 × 85.32
  4. Step 4: Simplify right side
    103.08x = 13,240.81
  5. Step 5: Solve for x
    x = 13,240.81/103.08
  6. Step 6: Final answer
    x = 128.45

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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.