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Finding the Fourth Proportional to 659.87, 989.86 and 221.10

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Solution

The fourth proportional to 659.87, 989.86 and 221.10 is: 331.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    659.87 : 989.86 = 221.10 : x
  2. Step 2: Convert to fraction form
    659.87/989.86 = 221.10/x
  3. Step 3: Cross multiply
    659.87x = 989.86 × 221.10
  4. Step 4: Simplify right side
    659.87x = 218,858.05
  5. Step 5: Solve for x
    x = 218,858.05/659.87
  6. Step 6: Final answer
    x = 331.67

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.