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Finding the Fourth Proportional to 661.08, 912.26 and 399.08

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Solution

The fourth proportional to 661.08, 912.26 and 399.08 is: 550.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    661.08 : 912.26 = 399.08 : x
  2. Step 2: Convert to fraction form
    661.08/912.26 = 399.08/x
  3. Step 3: Cross multiply
    661.08x = 912.26 × 399.08
  4. Step 4: Simplify right side
    661.08x = 364,064.72
  5. Step 5: Solve for x
    x = 364,064.72/661.08
  6. Step 6: Final answer
    x = 550.71

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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.