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Finding the Fourth Proportional to 66.20, 99.12 and 39.10

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Solution

The fourth proportional to 66.20, 99.12 and 39.10 is: 58.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    66.20 : 99.12 = 39.10 : x
  2. Step 2: Convert to fraction form
    66.20/99.12 = 39.10/x
  3. Step 3: Cross multiply
    66.20x = 99.12 × 39.10
  4. Step 4: Simplify right side
    66.20x = 3,875.59
  5. Step 5: Solve for x
    x = 3,875.59/66.20
  6. Step 6: Final answer
    x = 58.54

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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.