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Finding the Fourth Proportional to 782.22, 1,079.47 and 428.15

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Solution

The fourth proportional to 782.22, 1,079.47 and 428.15 is: 590.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    782.22 : 1,079.47 = 428.15 : x
  2. Step 2: Convert to fraction form
    782.22/1,079.47 = 428.15/x
  3. Step 3: Cross multiply
    782.22x = 1,079.47 × 428.15
  4. Step 4: Simplify right side
    782.22x = 462,169.83
  5. Step 5: Solve for x
    x = 462,169.83/782.22
  6. Step 6: Final answer
    x = 590.84

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.