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Finding the Fourth Proportional to 42.30, 63.36 and 28.78

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Solution

The fourth proportional to 42.30, 63.36 and 28.78 is: 43.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    42.30 : 63.36 = 28.78 : x
  2. Step 2: Convert to fraction form
    42.30/63.36 = 28.78/x
  3. Step 3: Cross multiply
    42.30x = 63.36 × 28.78
  4. Step 4: Simplify right side
    42.30x = 1,823.50
  5. Step 5: Solve for x
    x = 1,823.50/42.30
  6. Step 6: Final answer
    x = 43.11

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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.