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Finding the Fourth Proportional to 103.88, 143.40 and 65.12

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Solution

The fourth proportional to 103.88, 143.40 and 65.12 is: 89.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    103.88 : 143.40 = 65.12 : x
  2. Step 2: Convert to fraction form
    103.88/143.40 = 65.12/x
  3. Step 3: Cross multiply
    103.88x = 143.40 × 65.12
  4. Step 4: Simplify right side
    103.88x = 9,338.21
  5. Step 5: Solve for x
    x = 9,338.21/103.88
  6. Step 6: Final answer
    x = 89.89

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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.