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Finding the Fourth Proportional to 102.88, 155.04 and 90.88

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Solution

The fourth proportional to 102.88, 155.04 and 90.88 is: 136.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    102.88 : 155.04 = 90.88 : x
  2. Step 2: Convert to fraction form
    102.88/155.04 = 90.88/x
  3. Step 3: Cross multiply
    102.88x = 155.04 × 90.88
  4. Step 4: Simplify right side
    102.88x = 14,090.04
  5. Step 5: Solve for x
    x = 14,090.04/102.88
  6. Step 6: Final answer
    x = 136.96

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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.