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Finding the Fourth Proportional to 103.55, 155.15 and 71.42

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Solution

The fourth proportional to 103.55, 155.15 and 71.42 is: 107.01

Step by Step Solution

  1. Step 1: Write the proportion equation
    103.55 : 155.15 = 71.42 : x
  2. Step 2: Convert to fraction form
    103.55/155.15 = 71.42/x
  3. Step 3: Cross multiply
    103.55x = 155.15 × 71.42
  4. Step 4: Simplify right side
    103.55x = 11,080.46
  5. Step 5: Solve for x
    x = 11,080.46/103.55
  6. Step 6: Final answer
    x = 107.01

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.