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Finding the Fourth Proportional to 420.09, 625.91 and 396.51

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Solution

The fourth proportional to 420.09, 625.91 and 396.51 is: 590.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.09 : 625.91 = 396.51 : x
  2. Step 2: Convert to fraction form
    420.09/625.91 = 396.51/x
  3. Step 3: Cross multiply
    420.09x = 625.91 × 396.51
  4. Step 4: Simplify right side
    420.09x = 248,177.02
  5. Step 5: Solve for x
    x = 248,177.02/420.09
  6. Step 6: Final answer
    x = 590.77

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.