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Finding the Fourth Proportional to 62.80, 86.57 and 47.31

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Solution

The fourth proportional to 62.80, 86.57 and 47.31 is: 65.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    62.80 : 86.57 = 47.31 : x
  2. Step 2: Convert to fraction form
    62.80/86.57 = 47.31/x
  3. Step 3: Cross multiply
    62.80x = 86.57 × 47.31
  4. Step 4: Simplify right side
    62.80x = 4,095.49
  5. Step 5: Solve for x
    x = 4,095.49/62.80
  6. Step 6: Final answer
    x = 65.21

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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.