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Finding the Fourth Proportional to 643.99, 888.63 and 395.32

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Solution

The fourth proportional to 643.99, 888.63 and 395.32 is: 545.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.99 : 888.63 = 395.32 : x
  2. Step 2: Convert to fraction form
    643.99/888.63 = 395.32/x
  3. Step 3: Cross multiply
    643.99x = 888.63 × 395.32
  4. Step 4: Simplify right side
    643.99x = 351,288.77
  5. Step 5: Solve for x
    x = 351,288.77/643.99
  6. Step 6: Final answer
    x = 545.49

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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.