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Finding the Fourth Proportional to 71.92, 99.21 and 51.18

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Solution

The fourth proportional to 71.92, 99.21 and 51.18 is: 70.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    71.92 : 99.21 = 51.18 : x
  2. Step 2: Convert to fraction form
    71.92/99.21 = 51.18/x
  3. Step 3: Cross multiply
    71.92x = 99.21 × 51.18
  4. Step 4: Simplify right side
    71.92x = 5,077.57
  5. Step 5: Solve for x
    x = 5,077.57/71.92
  6. Step 6: Final answer
    x = 70.60

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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.