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Finding the Fourth Proportional to 1,131, 1,560.78 and 665.34

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Solution

The fourth proportional to 1,131, 1,560.78 and 665.34 is: 918.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,131 : 1,560.78 = 665.34 : x
  2. Step 2: Convert to fraction form
    1,131/1,560.78 = 665.34/x
  3. Step 3: Cross multiply
    1,131x = 1,560.78 × 665.34
  4. Step 4: Simplify right side
    1,131x = 1,038,449.37
  5. Step 5: Solve for x
    x = 1,038,449.37/1,131
  6. Step 6: Final answer
    x = 918.17

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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.