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Finding the Fourth Proportional to 661.21, 912.59 and 381.62

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Solution

The fourth proportional to 661.21, 912.59 and 381.62 is: 526.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    661.21 : 912.59 = 381.62 : x
  2. Step 2: Convert to fraction form
    661.21/912.59 = 381.62/x
  3. Step 3: Cross multiply
    661.21x = 912.59 × 381.62
  4. Step 4: Simplify right side
    661.21x = 348,265.83
  5. Step 5: Solve for x
    x = 348,265.83/661.21
  6. Step 6: Final answer
    x = 526.71

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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.