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Finding the Fourth Proportional to 72.91, 108.55 and 71.90

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Solution

The fourth proportional to 72.91, 108.55 and 71.90 is: 107.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    72.91 : 108.55 = 71.90 : x
  2. Step 2: Convert to fraction form
    72.91/108.55 = 71.90/x
  3. Step 3: Cross multiply
    72.91x = 108.55 × 71.90
  4. Step 4: Simplify right side
    72.91x = 7,804.75
  5. Step 5: Solve for x
    x = 7,804.75/72.91
  6. Step 6: Final answer
    x = 107.05

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.