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Finding the Fourth Proportional to 76.21, 105.06 and 71.75

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Solution

The fourth proportional to 76.21, 105.06 and 71.75 is: 98.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    76.21 : 105.06 = 71.75 : x
  2. Step 2: Convert to fraction form
    76.21/105.06 = 71.75/x
  3. Step 3: Cross multiply
    76.21x = 105.06 × 71.75
  4. Step 4: Simplify right side
    76.21x = 7,538.06
  5. Step 5: Solve for x
    x = 7,538.06/76.21
  6. Step 6: Final answer
    x = 98.91

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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.