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Finding the Fourth Proportional to 728.40, 1,005.62 and 492.76

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Solution

The fourth proportional to 728.40, 1,005.62 and 492.76 is: 680.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    728.40 : 1,005.62 = 492.76 : x
  2. Step 2: Convert to fraction form
    728.40/1,005.62 = 492.76/x
  3. Step 3: Cross multiply
    728.40x = 1,005.62 × 492.76
  4. Step 4: Simplify right side
    728.40x = 495,529.31
  5. Step 5: Solve for x
    x = 495,529.31/728.40
  6. Step 6: Final answer
    x = 680.30

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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.