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Finding the Fourth Proportional to 317.79, 440.71 and 307.80

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Solution

The fourth proportional to 317.79, 440.71 and 307.80 is: 426.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    317.79 : 440.71 = 307.80 : x
  2. Step 2: Convert to fraction form
    317.79/440.71 = 307.80/x
  3. Step 3: Cross multiply
    317.79x = 440.71 × 307.80
  4. Step 4: Simplify right side
    317.79x = 135,649.77
  5. Step 5: Solve for x
    x = 135,649.77/317.79
  6. Step 6: Final answer
    x = 426.85

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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.