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Finding the Fourth Proportional to 667.80, 1,002.90 and 485.40

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Solution

The fourth proportional to 667.80, 1,002.90 and 485.40 is: 728.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    667.80 : 1,002.90 = 485.40 : x
  2. Step 2: Convert to fraction form
    667.80/1,002.90 = 485.40/x
  3. Step 3: Cross multiply
    667.80x = 1,002.90 × 485.40
  4. Step 4: Simplify right side
    667.80x = 486,807.66
  5. Step 5: Solve for x
    x = 486,807.66/667.80
  6. Step 6: Final answer
    x = 728.97

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.