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Finding the Fourth Proportional to 781.81, 1,079.10 and 450.28

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Solution

The fourth proportional to 781.81, 1,079.10 and 450.28 is: 621.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    781.81 : 1,079.10 = 450.28 : x
  2. Step 2: Convert to fraction form
    781.81/1,079.10 = 450.28/x
  3. Step 3: Cross multiply
    781.81x = 1,079.10 × 450.28
  4. Step 4: Simplify right side
    781.81x = 485,894.45
  5. Step 5: Solve for x
    x = 485,894.45/781.81
  6. Step 6: Final answer
    x = 621.50

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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.