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Finding the Fourth Proportional to 1,280.36, 1,921.08 and 761.35

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Solution

The fourth proportional to 1,280.36, 1,921.08 and 761.35 is: 1,142.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,280.36 : 1,921.08 = 761.35 : x
  2. Step 2: Convert to fraction form
    1,280.36/1,921.08 = 761.35/x
  3. Step 3: Cross multiply
    1,280.36x = 1,921.08 × 761.35
  4. Step 4: Simplify right side
    1,280.36x = 1,462,614.26
  5. Step 5: Solve for x
    x = 1,462,614.26/1,280.36
  6. Step 6: Final answer
    x = 1,142.35

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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.