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Finding the Fourth Proportional to 72.99, 100.67 and 65.79

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Solution

The fourth proportional to 72.99, 100.67 and 65.79 is: 90.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    72.99 : 100.67 = 65.79 : x
  2. Step 2: Convert to fraction form
    72.99/100.67 = 65.79/x
  3. Step 3: Cross multiply
    72.99x = 100.67 × 65.79
  4. Step 4: Simplify right side
    72.99x = 6,622.75
  5. Step 5: Solve for x
    x = 6,622.75/72.99
  6. Step 6: Final answer
    x = 90.74

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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.