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Finding the Fourth Proportional to 66.20, 91.40 and 60.72

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Solution

The fourth proportional to 66.20, 91.40 and 60.72 is: 83.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    66.20 : 91.40 = 60.72 : x
  2. Step 2: Convert to fraction form
    66.20/91.40 = 60.72/x
  3. Step 3: Cross multiply
    66.20x = 91.40 × 60.72
  4. Step 4: Simplify right side
    66.20x = 5,549.81
  5. Step 5: Solve for x
    x = 5,549.81/66.20
  6. Step 6: Final answer
    x = 83.83

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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.