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Finding the Fourth Proportional to 45.78, 68.75 and 21.75

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Solution

The fourth proportional to 45.78, 68.75 and 21.75 is: 32.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    45.78 : 68.75 = 21.75 : x
  2. Step 2: Convert to fraction form
    45.78/68.75 = 21.75/x
  3. Step 3: Cross multiply
    45.78x = 68.75 × 21.75
  4. Step 4: Simplify right side
    45.78x = 1,495.20
  5. Step 5: Solve for x
    x = 1,495.20/45.78
  6. Step 6: Final answer
    x = 32.66

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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.