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Finding the Fourth Proportional to 66.55, 99.81 and 65.86

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Solution

The fourth proportional to 66.55, 99.81 and 65.86 is: 98.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    66.55 : 99.81 = 65.86 : x
  2. Step 2: Convert to fraction form
    66.55/99.81 = 65.86/x
  3. Step 3: Cross multiply
    66.55x = 99.81 × 65.86
  4. Step 4: Simplify right side
    66.55x = 6,573.49
  5. Step 5: Solve for x
    x = 6,573.49/66.55
  6. Step 6: Final answer
    x = 98.78

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.