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Finding the Fourth Proportional to 685.37, 945.80 and 489.15

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Solution

The fourth proportional to 685.37, 945.80 and 489.15 is: 675.02

Step by Step Solution

  1. Step 1: Write the proportion equation
    685.37 : 945.80 = 489.15 : x
  2. Step 2: Convert to fraction form
    685.37/945.80 = 489.15/x
  3. Step 3: Cross multiply
    685.37x = 945.80 × 489.15
  4. Step 4: Simplify right side
    685.37x = 462,638.07
  5. Step 5: Solve for x
    x = 462,638.07/685.37
  6. Step 6: Final answer
    x = 675.02

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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.