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Finding the Fourth Proportional to 102.87, 142.02 and 66.09

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Solution

The fourth proportional to 102.87, 142.02 and 66.09 is: 91.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    102.87 : 142.02 = 66.09 : x
  2. Step 2: Convert to fraction form
    102.87/142.02 = 66.09/x
  3. Step 3: Cross multiply
    102.87x = 142.02 × 66.09
  4. Step 4: Simplify right side
    102.87x = 9,386.10
  5. Step 5: Solve for x
    x = 9,386.10/102.87
  6. Step 6: Final answer
    x = 91.25

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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.