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Finding the Fourth Proportional to 71.90, 98.69 and 65.73

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Solution

The fourth proportional to 71.90, 98.69 and 65.73 is: 90.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    71.90 : 98.69 = 65.73 : x
  2. Step 2: Convert to fraction form
    71.90/98.69 = 65.73/x
  3. Step 3: Cross multiply
    71.90x = 98.69 × 65.73
  4. Step 4: Simplify right side
    71.90x = 6,486.89
  5. Step 5: Solve for x
    x = 6,486.89/71.90
  6. Step 6: Final answer
    x = 90.22

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.