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Finding the Fourth Proportional to 221.30, 305.37 and 128.03

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Solution

The fourth proportional to 221.30, 305.37 and 128.03 is: 176.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    221.30 : 305.37 = 128.03 : x
  2. Step 2: Convert to fraction form
    221.30/305.37 = 128.03/x
  3. Step 3: Cross multiply
    221.30x = 305.37 × 128.03
  4. Step 4: Simplify right side
    221.30x = 39,096.52
  5. Step 5: Solve for x
    x = 39,096.52/221.30
  6. Step 6: Final answer
    x = 176.67

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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.