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Finding the Fourth Proportional to 687.58, 1,029.52 and 413.28

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Solution

The fourth proportional to 687.58, 1,029.52 and 413.28 is: 618.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    687.58 : 1,029.52 = 413.28 : x
  2. Step 2: Convert to fraction form
    687.58/1,029.52 = 413.28/x
  3. Step 3: Cross multiply
    687.58x = 1,029.52 × 413.28
  4. Step 4: Simplify right side
    687.58x = 425,480.03
  5. Step 5: Solve for x
    x = 425,480.03/687.58
  6. Step 6: Final answer
    x = 618.81

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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.