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Finding the Fourth Proportional to 486.34, 670.77 and 311.70

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Solution

The fourth proportional to 486.34, 670.77 and 311.70 is: 429.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    486.34 : 670.77 = 311.70 : x
  2. Step 2: Convert to fraction form
    486.34/670.77 = 311.70/x
  3. Step 3: Cross multiply
    486.34x = 670.77 × 311.70
  4. Step 4: Simplify right side
    486.34x = 209,079.01
  5. Step 5: Solve for x
    x = 209,079.01/486.34
  6. Step 6: Final answer
    x = 429.90

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.