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Finding the Fourth Proportional to 928.65, 1,280.05 and 629.80

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Solution

The fourth proportional to 928.65, 1,280.05 and 629.80 is: 868.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    928.65 : 1,280.05 = 629.80 : x
  2. Step 2: Convert to fraction form
    928.65/1,280.05 = 629.80/x
  3. Step 3: Cross multiply
    928.65x = 1,280.05 × 629.80
  4. Step 4: Simplify right side
    928.65x = 806,175.49
  5. Step 5: Solve for x
    x = 806,175.49/928.65
  6. Step 6: Final answer
    x = 868.12

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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.