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Finding the Fourth Proportional to 71.83, 99.21 and 55.65

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Solution

The fourth proportional to 71.83, 99.21 and 55.65 is: 76.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    71.83 : 99.21 = 55.65 : x
  2. Step 2: Convert to fraction form
    71.83/99.21 = 55.65/x
  3. Step 3: Cross multiply
    71.83x = 99.21 × 55.65
  4. Step 4: Simplify right side
    71.83x = 5,521.04
  5. Step 5: Solve for x
    x = 5,521.04/71.83
  6. Step 6: Final answer
    x = 76.86

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.