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Finding the Fourth Proportional to 309.70, 464.10 and 213.40

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Solution

The fourth proportional to 309.70, 464.10 and 213.40 is: 319.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    309.70 : 464.10 = 213.40 : x
  2. Step 2: Convert to fraction form
    309.70/464.10 = 213.40/x
  3. Step 3: Cross multiply
    309.70x = 464.10 × 213.40
  4. Step 4: Simplify right side
    309.70x = 99,038.94
  5. Step 5: Solve for x
    x = 99,038.94/309.70
  6. Step 6: Final answer
    x = 319.79

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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.