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Finding the Fourth Proportional to 1,280.94, 1,921.89 and 511.50

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Solution

The fourth proportional to 1,280.94, 1,921.89 and 511.50 is: 767.44

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,280.94 : 1,921.89 = 511.50 : x
  2. Step 2: Convert to fraction form
    1,280.94/1,921.89 = 511.50/x
  3. Step 3: Cross multiply
    1,280.94x = 1,921.89 × 511.50
  4. Step 4: Simplify right side
    1,280.94x = 983,046.74
  5. Step 5: Solve for x
    x = 983,046.74/1,280.94
  6. Step 6: Final answer
    x = 767.44

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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.