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Finding the Fourth Proportional to 664.30, 916.83 and 398.86

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Solution

The fourth proportional to 664.30, 916.83 and 398.86 is: 550.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    664.30 : 916.83 = 398.86 : x
  2. Step 2: Convert to fraction form
    664.30/916.83 = 398.86/x
  3. Step 3: Cross multiply
    664.30x = 916.83 × 398.86
  4. Step 4: Simplify right side
    664.30x = 365,686.81
  5. Step 5: Solve for x
    x = 365,686.81/664.30
  6. Step 6: Final answer
    x = 550.48

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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.