Home / 1,209.40-1,814.10-387.70

Finding the Fourth Proportional to 1,209.40, 1,814.10 and 387.70

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Solution

The fourth proportional to 1,209.40, 1,814.10 and 387.70 is: 581.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,209.40 : 1,814.10 = 387.70 : x
  2. Step 2: Convert to fraction form
    1,209.40/1,814.10 = 387.70/x
  3. Step 3: Cross multiply
    1,209.40x = 1,814.10 × 387.70
  4. Step 4: Simplify right side
    1,209.40x = 703,326.57
  5. Step 5: Solve for x
    x = 703,326.57/1,209.40
  6. Step 6: Final answer
    x = 581.55

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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.