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Finding the Fourth Proportional to 45.90, 68.82 and 21.90

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Solution

The fourth proportional to 45.90, 68.82 and 21.90 is: 32.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    45.90 : 68.82 = 21.90 : x
  2. Step 2: Convert to fraction form
    45.90/68.82 = 21.90/x
  3. Step 3: Cross multiply
    45.90x = 68.82 × 21.90
  4. Step 4: Simplify right side
    45.90x = 1,507.16
  5. Step 5: Solve for x
    x = 1,507.16/45.90
  6. Step 6: Final answer
    x = 32.84

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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.