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Finding the Fourth Proportional to 781.66, 1,078.81 and 450.08

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Solution

The fourth proportional to 781.66, 1,078.81 and 450.08 is: 621.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    781.66 : 1,078.81 = 450.08 : x
  2. Step 2: Convert to fraction form
    781.66/1,078.81 = 450.08/x
  3. Step 3: Cross multiply
    781.66x = 1,078.81 × 450.08
  4. Step 4: Simplify right side
    781.66x = 485,548.33
  5. Step 5: Solve for x
    x = 485,548.33/781.66
  6. Step 6: Final answer
    x = 621.17

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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.