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Finding the Fourth Proportional to 102.78, 154.21 and 48.72

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Solution

The fourth proportional to 102.78, 154.21 and 48.72 is: 73.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    102.78 : 154.21 = 48.72 : x
  2. Step 2: Convert to fraction form
    102.78/154.21 = 48.72/x
  3. Step 3: Cross multiply
    102.78x = 154.21 × 48.72
  4. Step 4: Simplify right side
    102.78x = 7,513.11
  5. Step 5: Solve for x
    x = 7,513.11/102.78
  6. Step 6: Final answer
    x = 73.10

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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.