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Finding the Fourth Proportional to 661.22, 912.58 and 399.19

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Solution

The fourth proportional to 661.22, 912.58 and 399.19 is: 550.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    661.22 : 912.58 = 399.19 : x
  2. Step 2: Convert to fraction form
    661.22/912.58 = 399.19/x
  3. Step 3: Cross multiply
    661.22x = 912.58 × 399.19
  4. Step 4: Simplify right side
    661.22x = 364,289.53
  5. Step 5: Solve for x
    x = 364,289.53/661.22
  6. Step 6: Final answer
    x = 550.93

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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.