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Finding the Fourth Proportional to 840, 1,159.36 and 490.88

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Solution

The fourth proportional to 840, 1,159.36 and 490.88 is: 677.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    840 : 1,159.36 = 490.88 : x
  2. Step 2: Convert to fraction form
    840/1,159.36 = 490.88/x
  3. Step 3: Cross multiply
    840x = 1,159.36 × 490.88
  4. Step 4: Simplify right side
    840x = 569,106.64
  5. Step 5: Solve for x
    x = 569,106.64/840
  6. Step 6: Final answer
    x = 677.51

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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.