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Finding the Fourth Proportional to 826.72, 1,240 and 278.88

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Solution

The fourth proportional to 826.72, 1,240 and 278.88 is: 418.29

Step by Step Solution

  1. Step 1: Write the proportion equation
    826.72 : 1,240 = 278.88 : x
  2. Step 2: Convert to fraction form
    826.72/1,240 = 278.88/x
  3. Step 3: Cross multiply
    826.72x = 1,240 × 278.88
  4. Step 4: Simplify right side
    826.72x = 345,811.20
  5. Step 5: Solve for x
    x = 345,811.20/826.72
  6. Step 6: Final answer
    x = 418.29

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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.