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Finding the Fourth Proportional to 685.68, 945.96 and 478.80

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Solution

The fourth proportional to 685.68, 945.96 and 478.80 is: 660.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    685.68 : 945.96 = 478.80 : x
  2. Step 2: Convert to fraction form
    685.68/945.96 = 478.80/x
  3. Step 3: Cross multiply
    685.68x = 945.96 × 478.80
  4. Step 4: Simplify right side
    685.68x = 452,925.65
  5. Step 5: Solve for x
    x = 452,925.65/685.68
  6. Step 6: Final answer
    x = 660.55

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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.