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Finding the Fourth Proportional to 661.11, 912.28 and 381.15

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Solution

The fourth proportional to 661.11, 912.28 and 381.15 is: 525.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    661.11 : 912.28 = 381.15 : x
  2. Step 2: Convert to fraction form
    661.11/912.28 = 381.15/x
  3. Step 3: Cross multiply
    661.11x = 912.28 × 381.15
  4. Step 4: Simplify right side
    661.11x = 347,715.52
  5. Step 5: Solve for x
    x = 347,715.52/661.11
  6. Step 6: Final answer
    x = 525.96

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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.