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Finding the Fourth Proportional to 643.79, 888.53 and 381.81

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Solution

The fourth proportional to 643.79, 888.53 and 381.81 is: 526.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.79 : 888.53 = 381.81 : x
  2. Step 2: Convert to fraction form
    643.79/888.53 = 381.81/x
  3. Step 3: Cross multiply
    643.79x = 888.53 × 381.81
  4. Step 4: Simplify right side
    643.79x = 339,247.73
  5. Step 5: Solve for x
    x = 339,247.73/643.79
  6. Step 6: Final answer
    x = 526.96

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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.