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Finding the Fourth Proportional to 782.64, 1,078.20 and 649.04

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Solution

The fourth proportional to 782.64, 1,078.20 and 649.04 is: 894.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    782.64 : 1,078.20 = 649.04 : x
  2. Step 2: Convert to fraction form
    782.64/1,078.20 = 649.04/x
  3. Step 3: Cross multiply
    782.64x = 1,078.20 × 649.04
  4. Step 4: Simplify right side
    782.64x = 699,794.93
  5. Step 5: Solve for x
    x = 699,794.93/782.64
  6. Step 6: Final answer
    x = 894.15

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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.