Home / 1,212.71-1,819.29-390.90

Finding the Fourth Proportional to 1,212.71, 1,819.29 and 390.90

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Solution

The fourth proportional to 1,212.71, 1,819.29 and 390.90 is: 586.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,212.71 : 1,819.29 = 390.90 : x
  2. Step 2: Convert to fraction form
    1,212.71/1,819.29 = 390.90/x
  3. Step 3: Cross multiply
    1,212.71x = 1,819.29 × 390.90
  4. Step 4: Simplify right side
    1,212.71x = 711,160.46
  5. Step 5: Solve for x
    x = 711,160.46/1,212.71
  6. Step 6: Final answer
    x = 586.42

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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.