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Finding the Fourth Proportional to 485.63, 670.39 and 311.08

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Solution

The fourth proportional to 485.63, 670.39 and 311.08 is: 429.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    485.63 : 670.39 = 311.08 : x
  2. Step 2: Convert to fraction form
    485.63/670.39 = 311.08/x
  3. Step 3: Cross multiply
    485.63x = 670.39 × 311.08
  4. Step 4: Simplify right side
    485.63x = 208,541.57
  5. Step 5: Solve for x
    x = 208,541.57/485.63
  6. Step 6: Final answer
    x = 429.42

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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.