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Finding the Fourth Proportional to 219.38, 328.72 and 121.80

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Solution

The fourth proportional to 219.38, 328.72 and 121.80 is: 182.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    219.38 : 328.72 = 121.80 : x
  2. Step 2: Convert to fraction form
    219.38/328.72 = 121.80/x
  3. Step 3: Cross multiply
    219.38x = 328.72 × 121.80
  4. Step 4: Simplify right side
    219.38x = 40,038.10
  5. Step 5: Solve for x
    x = 40,038.10/219.38
  6. Step 6: Final answer
    x = 182.51

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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.