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Finding the Fourth Proportional to 781.47, 1,078.43 and 427.37

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Solution

The fourth proportional to 781.47, 1,078.43 and 427.37 is: 589.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    781.47 : 1,078.43 = 427.37 : x
  2. Step 2: Convert to fraction form
    781.47/1,078.43 = 427.37/x
  3. Step 3: Cross multiply
    781.47x = 1,078.43 × 427.37
  4. Step 4: Simplify right side
    781.47x = 460,881.10
  5. Step 5: Solve for x
    x = 460,881.10/781.47
  6. Step 6: Final answer
    x = 589.76

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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.