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Finding the Fourth Proportional to 66.60, 91.20 and 66.60

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Solution

The fourth proportional to 66.60, 91.20 and 66.60 is: 91.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    66.60 : 91.20 = 66.60 : x
  2. Step 2: Convert to fraction form
    66.60/91.20 = 66.60/x
  3. Step 3: Cross multiply
    66.60x = 91.20 × 66.60
  4. Step 4: Simplify right side
    66.60x = 6,073.92
  5. Step 5: Solve for x
    x = 6,073.92/66.60
  6. Step 6: Final answer
    x = 91.20

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.