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Finding the Fourth Proportional to 989.70, 1,365.30 and 843.90

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Solution

The fourth proportional to 989.70, 1,365.30 and 843.90 is: 1,164.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    989.70 : 1,365.30 = 843.90 : x
  2. Step 2: Convert to fraction form
    989.70/1,365.30 = 843.90/x
  3. Step 3: Cross multiply
    989.70x = 1,365.30 × 843.90
  4. Step 4: Simplify right side
    989.70x = 1,152,176.67
  5. Step 5: Solve for x
    x = 1,152,176.67/989.70
  6. Step 6: Final answer
    x = 1,164.17

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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.