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Finding the Fourth Proportional to 1,209.81, 1,814.40 and 387.66

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Solution

The fourth proportional to 1,209.81, 1,814.40 and 387.66 is: 581.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,209.81 : 1,814.40 = 387.66 : x
  2. Step 2: Convert to fraction form
    1,209.81/1,814.40 = 387.66/x
  3. Step 3: Cross multiply
    1,209.81x = 1,814.40 × 387.66
  4. Step 4: Simplify right side
    1,209.81x = 703,370.30
  5. Step 5: Solve for x
    x = 703,370.30/1,209.81
  6. Step 6: Final answer
    x = 581.39

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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.