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Finding the Fourth Proportional to 426.58, 643.01 and 391.47

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Solution

The fourth proportional to 426.58, 643.01 and 391.47 is: 590.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    426.58 : 643.01 = 391.47 : x
  2. Step 2: Convert to fraction form
    426.58/643.01 = 391.47/x
  3. Step 3: Cross multiply
    426.58x = 643.01 × 391.47
  4. Step 4: Simplify right side
    426.58x = 251,720.58
  5. Step 5: Solve for x
    x = 251,720.58/426.58
  6. Step 6: Final answer
    x = 590.09

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.