Home / 1,139.04-1,708.65-408.78

Finding the Fourth Proportional to 1,139.04, 1,708.65 and 408.78

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Solution

The fourth proportional to 1,139.04, 1,708.65 and 408.78 is: 613.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,139.04 : 1,708.65 = 408.78 : x
  2. Step 2: Convert to fraction form
    1,139.04/1,708.65 = 408.78/x
  3. Step 3: Cross multiply
    1,139.04x = 1,708.65 × 408.78
  4. Step 4: Simplify right side
    1,139.04x = 698,461.95
  5. Step 5: Solve for x
    x = 698,461.95/1,139.04
  6. Step 6: Final answer
    x = 613.20

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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.