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Finding the Fourth Proportional to 68.30, 102.45 and 20.21

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Solution

The fourth proportional to 68.30, 102.45 and 20.21 is: 30.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    68.30 : 102.45 = 20.21 : x
  2. Step 2: Convert to fraction form
    68.30/102.45 = 20.21/x
  3. Step 3: Cross multiply
    68.30x = 102.45 × 20.21
  4. Step 4: Simplify right side
    68.30x = 2,070.51
  5. Step 5: Solve for x
    x = 2,070.51/68.30
  6. Step 6: Final answer
    x = 30.32

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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.