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Finding the Fourth Proportional to 781.85, 1,078.79 and 450.19

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Solution

The fourth proportional to 781.85, 1,078.79 and 450.19 is: 621.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    781.85 : 1,078.79 = 450.19 : x
  2. Step 2: Convert to fraction form
    781.85/1,078.79 = 450.19/x
  3. Step 3: Cross multiply
    781.85x = 1,078.79 × 450.19
  4. Step 4: Simplify right side
    781.85x = 485,658.90
  5. Step 5: Solve for x
    x = 485,658.90/781.85
  6. Step 6: Final answer
    x = 621.17

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Double scale
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1.5x scale

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.