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Finding the Fourth Proportional to 223.20, 307.80 and 212.40

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Solution

The fourth proportional to 223.20, 307.80 and 212.40 is: 292.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    223.20 : 307.80 = 212.40 : x
  2. Step 2: Convert to fraction form
    223.20/307.80 = 212.40/x
  3. Step 3: Cross multiply
    223.20x = 307.80 × 212.40
  4. Step 4: Simplify right side
    223.20x = 65,376.72
  5. Step 5: Solve for x
    x = 65,376.72/223.20
  6. Step 6: Final answer
    x = 292.91

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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.