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Finding the Fourth Proportional to 782.16, 1,079.35 and 428.09

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Solution

The fourth proportional to 782.16, 1,079.35 and 428.09 is: 590.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    782.16 : 1,079.35 = 428.09 : x
  2. Step 2: Convert to fraction form
    782.16/1,079.35 = 428.09/x
  3. Step 3: Cross multiply
    782.16x = 1,079.35 × 428.09
  4. Step 4: Simplify right side
    782.16x = 462,058.94
  5. Step 5: Solve for x
    x = 462,058.94/782.16
  6. Step 6: Final answer
    x = 590.75

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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.