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Finding the Fourth Proportional to 76.31, 105.31 and 47.19

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Solution

The fourth proportional to 76.31, 105.31 and 47.19 is: 65.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    76.31 : 105.31 = 47.19 : x
  2. Step 2: Convert to fraction form
    76.31/105.31 = 47.19/x
  3. Step 3: Cross multiply
    76.31x = 105.31 × 47.19
  4. Step 4: Simplify right side
    76.31x = 4,969.34
  5. Step 5: Solve for x
    x = 4,969.34/76.31
  6. Step 6: Final answer
    x = 65.12

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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.