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Finding the Fourth Proportional to 485.82, 670.28 and 311.13

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Solution

The fourth proportional to 485.82, 670.28 and 311.13 is: 429.26

Step by Step Solution

  1. Step 1: Write the proportion equation
    485.82 : 670.28 = 311.13 : x
  2. Step 2: Convert to fraction form
    485.82/670.28 = 311.13/x
  3. Step 3: Cross multiply
    485.82x = 670.28 × 311.13
  4. Step 4: Simplify right side
    485.82x = 208,542.66
  5. Step 5: Solve for x
    x = 208,542.66/485.82
  6. Step 6: Final answer
    x = 429.26

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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.