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Finding the Fourth Proportional to 72.65, 108.15 and 71.87

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Solution

The fourth proportional to 72.65, 108.15 and 71.87 is: 106.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    72.65 : 108.15 = 71.87 : x
  2. Step 2: Convert to fraction form
    72.65/108.15 = 71.87/x
  3. Step 3: Cross multiply
    72.65x = 108.15 × 71.87
  4. Step 4: Simplify right side
    72.65x = 7,772.74
  5. Step 5: Solve for x
    x = 7,772.74/72.65
  6. Step 6: Final answer
    x = 106.99

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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.