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Finding the Fourth Proportional to 826.78, 1,240.14 and 313.78

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Solution

The fourth proportional to 826.78, 1,240.14 and 313.78 is: 470.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    826.78 : 1,240.14 = 313.78 : x
  2. Step 2: Convert to fraction form
    826.78/1,240.14 = 313.78/x
  3. Step 3: Cross multiply
    826.78x = 1,240.14 × 313.78
  4. Step 4: Simplify right side
    826.78x = 389,131.13
  5. Step 5: Solve for x
    x = 389,131.13/826.78
  6. Step 6: Final answer
    x = 470.66

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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.