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Finding the Fourth Proportional to 661.15, 912.59 and 381.57

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Solution

The fourth proportional to 661.15, 912.59 and 381.57 is: 526.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    661.15 : 912.59 = 381.57 : x
  2. Step 2: Convert to fraction form
    661.15/912.59 = 381.57/x
  3. Step 3: Cross multiply
    661.15x = 912.59 × 381.57
  4. Step 4: Simplify right side
    661.15x = 348,219.06
  5. Step 5: Solve for x
    x = 348,219.06/661.15
  6. Step 6: Final answer
    x = 526.68

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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.