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Finding the Fourth Proportional to 661.26, 912.78 and 399.27

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Solution

The fourth proportional to 661.26, 912.78 and 399.27 is: 551.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    661.26 : 912.78 = 399.27 : x
  2. Step 2: Convert to fraction form
    661.26/912.78 = 399.27/x
  3. Step 3: Cross multiply
    661.26x = 912.78 × 399.27
  4. Step 4: Simplify right side
    661.26x = 364,445.67
  5. Step 5: Solve for x
    x = 364,445.67/661.26
  6. Step 6: Final answer
    x = 551.14

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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.