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Finding the Fourth Proportional to 670.69, 1,005.81 and 259.69

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Solution

The fourth proportional to 670.69, 1,005.81 and 259.69 is: 389.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    670.69 : 1,005.81 = 259.69 : x
  2. Step 2: Convert to fraction form
    670.69/1,005.81 = 259.69/x
  3. Step 3: Cross multiply
    670.69x = 1,005.81 × 259.69
  4. Step 4: Simplify right side
    670.69x = 261,198.80
  5. Step 5: Solve for x
    x = 261,198.80/670.69
  6. Step 6: Final answer
    x = 389.45

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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.