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Finding the Fourth Proportional to 219.03, 328.57 and 90.78

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Solution

The fourth proportional to 219.03, 328.57 and 90.78 is: 136.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    219.03 : 328.57 = 90.78 : x
  2. Step 2: Convert to fraction form
    219.03/328.57 = 90.78/x
  3. Step 3: Cross multiply
    219.03x = 328.57 × 90.78
  4. Step 4: Simplify right side
    219.03x = 29,827.13
  5. Step 5: Solve for x
    x = 29,827.13/219.03
  6. Step 6: Final answer
    x = 136.18

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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.