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Finding the Fourth Proportional to 219.18, 328.78 and 56.87

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Solution

The fourth proportional to 219.18, 328.78 and 56.87 is: 85.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    219.18 : 328.78 = 56.87 : x
  2. Step 2: Convert to fraction form
    219.18/328.78 = 56.87/x
  3. Step 3: Cross multiply
    219.18x = 328.78 × 56.87
  4. Step 4: Simplify right side
    219.18x = 18,696.72
  5. Step 5: Solve for x
    x = 18,696.72/219.18
  6. Step 6: Final answer
    x = 85.30

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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.