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Finding the Fourth Proportional to 103.08, 142.09 and 64.20

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Solution

The fourth proportional to 103.08, 142.09 and 64.20 is: 88.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    103.08 : 142.09 = 64.20 : x
  2. Step 2: Convert to fraction form
    103.08/142.09 = 64.20/x
  3. Step 3: Cross multiply
    103.08x = 142.09 × 64.20
  4. Step 4: Simplify right side
    103.08x = 9,122.18
  5. Step 5: Solve for x
    x = 9,122.18/103.08
  6. Step 6: Final answer
    x = 88.50

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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.