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Finding the Fourth Proportional to 674.80, 1,011.90 and 309.40

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Solution

The fourth proportional to 674.80, 1,011.90 and 309.40 is: 463.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    674.80 : 1,011.90 = 309.40 : x
  2. Step 2: Convert to fraction form
    674.80/1,011.90 = 309.40/x
  3. Step 3: Cross multiply
    674.80x = 1,011.90 × 309.40
  4. Step 4: Simplify right side
    674.80x = 313,081.86
  5. Step 5: Solve for x
    x = 313,081.86/674.80
  6. Step 6: Final answer
    x = 463.96

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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.