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Finding the Fourth Proportional to 72.89, 100.81 and 71.67

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Solution

The fourth proportional to 72.89, 100.81 and 71.67 is: 99.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    72.89 : 100.81 = 71.67 : x
  2. Step 2: Convert to fraction form
    72.89/100.81 = 71.67/x
  3. Step 3: Cross multiply
    72.89x = 100.81 × 71.67
  4. Step 4: Simplify right side
    72.89x = 7,225.05
  5. Step 5: Solve for x
    x = 7,225.05/72.89
  6. Step 6: Final answer
    x = 99.12

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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.