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Finding the Fourth Proportional to 674.40, 1,011.60 and 309.90

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Solution

The fourth proportional to 674.40, 1,011.60 and 309.90 is: 464.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    674.40 : 1,011.60 = 309.90 : x
  2. Step 2: Convert to fraction form
    674.40/1,011.60 = 309.90/x
  3. Step 3: Cross multiply
    674.40x = 1,011.60 × 309.90
  4. Step 4: Simplify right side
    674.40x = 313,494.84
  5. Step 5: Solve for x
    x = 313,494.84/674.40
  6. Step 6: Final answer
    x = 464.85

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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.