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Finding the Fourth Proportional to 664.80, 916.32 and 487.68

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Solution

The fourth proportional to 664.80, 916.32 and 487.68 is: 672.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    664.80 : 916.32 = 487.68 : x
  2. Step 2: Convert to fraction form
    664.80/916.32 = 487.68/x
  3. Step 3: Cross multiply
    664.80x = 916.32 × 487.68
  4. Step 4: Simplify right side
    664.80x = 446,870.94
  5. Step 5: Solve for x
    x = 446,870.94/664.80
  6. Step 6: Final answer
    x = 672.19

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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.