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Finding the Fourth Proportional to 661.06, 912.05 and 399.14

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Solution

The fourth proportional to 661.06, 912.05 and 399.14 is: 550.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    661.06 : 912.05 = 399.14 : x
  2. Step 2: Convert to fraction form
    661.06/912.05 = 399.14/x
  3. Step 3: Cross multiply
    661.06x = 912.05 × 399.14
  4. Step 4: Simplify right side
    661.06x = 364,035.64
  5. Step 5: Solve for x
    x = 364,035.64/661.06
  6. Step 6: Final answer
    x = 550.68

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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.