Home / 1,278.49-1,916.50-412.20

Finding the Fourth Proportional to 1,278.49, 1,916.50 and 412.20

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Solution

The fourth proportional to 1,278.49, 1,916.50 and 412.20 is: 617.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,278.49 : 1,916.50 = 412.20 : x
  2. Step 2: Convert to fraction form
    1,278.49/1,916.50 = 412.20/x
  3. Step 3: Cross multiply
    1,278.49x = 1,916.50 × 412.20
  4. Step 4: Simplify right side
    1,278.49x = 789,981.30
  5. Step 5: Solve for x
    x = 789,981.30/1,278.49
  6. Step 6: Final answer
    x = 617.90

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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.