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Finding the Fourth Proportional to 68.10, 102.15 and 45.20

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Solution

The fourth proportional to 68.10, 102.15 and 45.20 is: 67.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    68.10 : 102.15 = 45.20 : x
  2. Step 2: Convert to fraction form
    68.10/102.15 = 45.20/x
  3. Step 3: Cross multiply
    68.10x = 102.15 × 45.20
  4. Step 4: Simplify right side
    68.10x = 4,617.18
  5. Step 5: Solve for x
    x = 4,617.18/68.10
  6. Step 6: Final answer
    x = 67.80

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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.