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Finding the Fourth Proportional to 661.23, 912.33 and 399.13

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Solution

The fourth proportional to 661.23, 912.33 and 399.13 is: 550.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    661.23 : 912.33 = 399.13 : x
  2. Step 2: Convert to fraction form
    661.23/912.33 = 399.13/x
  3. Step 3: Cross multiply
    661.23x = 912.33 × 399.13
  4. Step 4: Simplify right side
    661.23x = 364,135.99
  5. Step 5: Solve for x
    x = 364,135.99/661.23
  6. Step 6: Final answer
    x = 550.69

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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.