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Finding the Fourth Proportional to 219.38, 328.93 and 128.05

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Solution

The fourth proportional to 219.38, 328.93 and 128.05 is: 191.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    219.38 : 328.93 = 128.05 : x
  2. Step 2: Convert to fraction form
    219.38/328.93 = 128.05/x
  3. Step 3: Cross multiply
    219.38x = 328.93 × 128.05
  4. Step 4: Simplify right side
    219.38x = 42,118.34
  5. Step 5: Solve for x
    x = 42,118.34/219.38
  6. Step 6: Final answer
    x = 191.99

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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.