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Finding the Fourth Proportional to 102.45, 141.30 and 65.61

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Solution

The fourth proportional to 102.45, 141.30 and 65.61 is: 90.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    102.45 : 141.30 = 65.61 : x
  2. Step 2: Convert to fraction form
    102.45/141.30 = 65.61/x
  3. Step 3: Cross multiply
    102.45x = 141.30 × 65.61
  4. Step 4: Simplify right side
    102.45x = 9,270.69
  5. Step 5: Solve for x
    x = 9,270.69/102.45
  6. Step 6: Final answer
    x = 90.49

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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.