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Finding the Fourth Proportional to 1,080.19, 1,490.43 and 687.29

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Solution

The fourth proportional to 1,080.19, 1,490.43 and 687.29 is: 948.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,080.19 : 1,490.43 = 687.29 : x
  2. Step 2: Convert to fraction form
    1,080.19/1,490.43 = 687.29/x
  3. Step 3: Cross multiply
    1,080.19x = 1,490.43 × 687.29
  4. Step 4: Simplify right side
    1,080.19x = 1,024,346.96
  5. Step 5: Solve for x
    x = 1,024,346.96/1,080.19
  6. Step 6: Final answer
    x = 948.31

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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.