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Finding the Fourth Proportional to 103.90, 143.28 and 67.08

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Solution

The fourth proportional to 103.90, 143.28 and 67.08 is: 92.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    103.90 : 143.28 = 67.08 : x
  2. Step 2: Convert to fraction form
    103.90/143.28 = 67.08/x
  3. Step 3: Cross multiply
    103.90x = 143.28 × 67.08
  4. Step 4: Simplify right side
    103.90x = 9,610.17
  5. Step 5: Solve for x
    x = 9,610.17/103.90
  6. Step 6: Final answer
    x = 92.50

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.