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Finding the Fourth Proportional to 989.30, 1,365.14 and 611.12

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Solution

The fourth proportional to 989.30, 1,365.14 and 611.12 is: 843.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    989.30 : 1,365.14 = 611.12 : x
  2. Step 2: Convert to fraction form
    989.30/1,365.14 = 611.12/x
  3. Step 3: Cross multiply
    989.30x = 1,365.14 × 611.12
  4. Step 4: Simplify right side
    989.30x = 834,254.48
  5. Step 5: Solve for x
    x = 834,254.48/989.30
  6. Step 6: Final answer
    x = 843.28

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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.