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Finding the Fourth Proportional to 661.13, 912.36 and 428.66

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Solution

The fourth proportional to 661.13, 912.36 and 428.66 is: 591.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    661.13 : 912.36 = 428.66 : x
  2. Step 2: Convert to fraction form
    661.13/912.36 = 428.66/x
  3. Step 3: Cross multiply
    661.13x = 912.36 × 428.66
  4. Step 4: Simplify right side
    661.13x = 391,092.24
  5. Step 5: Solve for x
    x = 391,092.24/661.13
  6. Step 6: Final answer
    x = 591.55

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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.