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Finding the Fourth Proportional to 1,280.40, 1,920.42 and 500.82

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Solution

The fourth proportional to 1,280.40, 1,920.42 and 500.82 is: 751.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,280.40 : 1,920.42 = 500.82 : x
  2. Step 2: Convert to fraction form
    1,280.40/1,920.42 = 500.82/x
  3. Step 3: Cross multiply
    1,280.40x = 1,920.42 × 500.82
  4. Step 4: Simplify right side
    1,280.40x = 961,784.74
  5. Step 5: Solve for x
    x = 961,784.74/1,280.40
  6. Step 6: Final answer
    x = 751.16

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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.