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Finding the Fourth Proportional to 661.02, 912.08 and 381.21

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Solution

The fourth proportional to 661.02, 912.08 and 381.21 is: 525.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    661.02 : 912.08 = 381.21 : x
  2. Step 2: Convert to fraction form
    661.02/912.08 = 381.21/x
  3. Step 3: Cross multiply
    661.02x = 912.08 × 381.21
  4. Step 4: Simplify right side
    661.02x = 347,692.11
  5. Step 5: Solve for x
    x = 347,692.11/661.02
  6. Step 6: Final answer
    x = 525.99

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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.