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Finding the Fourth Proportional to 781.77, 1,078.85 and 427.69

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Solution

The fourth proportional to 781.77, 1,078.85 and 427.69 is: 590.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    781.77 : 1,078.85 = 427.69 : x
  2. Step 2: Convert to fraction form
    781.77/1,078.85 = 427.69/x
  3. Step 3: Cross multiply
    781.77x = 1,078.85 × 427.69
  4. Step 4: Simplify right side
    781.77x = 461,408.52
  5. Step 5: Solve for x
    x = 461,408.52/781.77
  6. Step 6: Final answer
    x = 590.21

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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.