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Finding the Fourth Proportional to 313.20, 469.80 and 221.40

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Solution

The fourth proportional to 313.20, 469.80 and 221.40 is: 332.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    313.20 : 469.80 = 221.40 : x
  2. Step 2: Convert to fraction form
    313.20/469.80 = 221.40/x
  3. Step 3: Cross multiply
    313.20x = 469.80 × 221.40
  4. Step 4: Simplify right side
    313.20x = 104,013.72
  5. Step 5: Solve for x
    x = 104,013.72/313.20
  6. Step 6: Final answer
    x = 332.10

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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.