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Finding the Fourth Proportional to 781.89, 1,078.99 and 427.81

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Solution

The fourth proportional to 781.89, 1,078.99 and 427.81 is: 590.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    781.89 : 1,078.99 = 427.81 : x
  2. Step 2: Convert to fraction form
    781.89/1,078.99 = 427.81/x
  3. Step 3: Cross multiply
    781.89x = 1,078.99 × 427.81
  4. Step 4: Simplify right side
    781.89x = 461,600.57
  5. Step 5: Solve for x
    x = 461,600.57/781.89
  6. Step 6: Final answer
    x = 590.37

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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.