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Finding the Fourth Proportional to 643.56, 888.24 and 381.66

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Solution

The fourth proportional to 643.56, 888.24 and 381.66 is: 526.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.56 : 888.24 = 381.66 : x
  2. Step 2: Convert to fraction form
    643.56/888.24 = 381.66/x
  3. Step 3: Cross multiply
    643.56x = 888.24 × 381.66
  4. Step 4: Simplify right side
    643.56x = 339,005.68
  5. Step 5: Solve for x
    x = 339,005.68/643.56
  6. Step 6: Final answer
    x = 526.77

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1.5x scale

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.