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Finding the Fourth Proportional to 317.46, 439.79 and 309.90

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Solution

The fourth proportional to 317.46, 439.79 and 309.90 is: 429.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    317.46 : 439.79 = 309.90 : x
  2. Step 2: Convert to fraction form
    317.46/439.79 = 309.90/x
  3. Step 3: Cross multiply
    317.46x = 439.79 × 309.90
  4. Step 4: Simplify right side
    317.46x = 136,290.92
  5. Step 5: Solve for x
    x = 136,290.92/317.46
  6. Step 6: Final answer
    x = 429.32

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Why These Related Problems?

These problems maintain the same ratio (1.39) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.