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Finding the Fourth Proportional to 992.77, 1,489.64 and 408.21

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Solution

The fourth proportional to 992.77, 1,489.64 and 408.21 is: 612.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    992.77 : 1,489.64 = 408.21 : x
  2. Step 2: Convert to fraction form
    992.77/1,489.64 = 408.21/x
  3. Step 3: Cross multiply
    992.77x = 1,489.64 × 408.21
  4. Step 4: Simplify right side
    992.77x = 608,080.61
  5. Step 5: Solve for x
    x = 608,080.61/992.77
  6. Step 6: Final answer
    x = 612.51

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.