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Finding the Fourth Proportional to 72.78, 107.88 and 71.63

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Solution

The fourth proportional to 72.78, 107.88 and 71.63 is: 106.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    72.78 : 107.88 = 71.63 : x
  2. Step 2: Convert to fraction form
    72.78/107.88 = 71.63/x
  3. Step 3: Cross multiply
    72.78x = 107.88 × 71.63
  4. Step 4: Simplify right side
    72.78x = 7,727.44
  5. Step 5: Solve for x
    x = 7,727.44/72.78
  6. Step 6: Final answer
    x = 106.18

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Why These Related Problems?

These problems maintain the same ratio (1.48) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.