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Finding the Fourth Proportional to 76.30, 105.21 and 71.83

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Solution

The fourth proportional to 76.30, 105.21 and 71.83 is: 99.04

Step by Step Solution

  1. Step 1: Write the proportion equation
    76.30 : 105.21 = 71.83 : x
  2. Step 2: Convert to fraction form
    76.30/105.21 = 71.83/x
  3. Step 3: Cross multiply
    76.30x = 105.21 × 71.83
  4. Step 4: Simplify right side
    76.30x = 7,556.87
  5. Step 5: Solve for x
    x = 7,556.87/76.30
  6. Step 6: Final answer
    x = 99.04

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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.