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Finding the Fourth Proportional to 891.50, 1,339.07 and 685.35

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Solution

The fourth proportional to 891.50, 1,339.07 and 685.35 is: 1,029.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    891.50 : 1,339.07 = 685.35 : x
  2. Step 2: Convert to fraction form
    891.50/1,339.07 = 685.35/x
  3. Step 3: Cross multiply
    891.50x = 1,339.07 × 685.35
  4. Step 4: Simplify right side
    891.50x = 917,728.20
  5. Step 5: Solve for x
    x = 917,728.20/891.50
  6. Step 6: Final answer
    x = 1,029.43

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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.