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Finding the Fourth Proportional to 661.52, 912.78 and 381.72

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Solution

The fourth proportional to 661.52, 912.78 and 381.72 is: 526.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    661.52 : 912.78 = 381.72 : x
  2. Step 2: Convert to fraction form
    661.52/912.78 = 381.72/x
  3. Step 3: Cross multiply
    661.52x = 912.78 × 381.72
  4. Step 4: Simplify right side
    661.52x = 348,426.38
  5. Step 5: Solve for x
    x = 348,426.38/661.52
  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.