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Finding the Fourth Proportional to 1,280.09, 1,920.42 and 458.36

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Solution

The fourth proportional to 1,280.09, 1,920.42 and 458.36 is: 687.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,280.09 : 1,920.42 = 458.36 : x
  2. Step 2: Convert to fraction form
    1,280.09/1,920.42 = 458.36/x
  3. Step 3: Cross multiply
    1,280.09x = 1,920.42 × 458.36
  4. Step 4: Simplify right side
    1,280.09x = 880,243.71
  5. Step 5: Solve for x
    x = 880,243.71/1,280.09
  6. Step 6: Final answer
    x = 687.64

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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.