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Finding the Fourth Proportional to 670.80, 1,005.98 and 259.90

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Solution

The fourth proportional to 670.80, 1,005.98 and 259.90 is: 389.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    670.80 : 1,005.98 = 259.90 : x
  2. Step 2: Convert to fraction form
    670.80/1,005.98 = 259.90/x
  3. Step 3: Cross multiply
    670.80x = 1,005.98 × 259.90
  4. Step 4: Simplify right side
    670.80x = 261,454.20
  5. Step 5: Solve for x
    x = 261,454.20/670.80
  6. Step 6: Final answer
    x = 389.76

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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.