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Finding the Fourth Proportional to 1,320.98, 1,821.29 and 988.74

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Solution

The fourth proportional to 1,320.98, 1,821.29 and 988.74 is: 1,363.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,320.98 : 1,821.29 = 988.74 : x
  2. Step 2: Convert to fraction form
    1,320.98/1,821.29 = 988.74/x
  3. Step 3: Cross multiply
    1,320.98x = 1,821.29 × 988.74
  4. Step 4: Simplify right side
    1,320.98x = 1,800,777.33
  5. Step 5: Solve for x
    x = 1,800,777.33/1,320.98
  6. Step 6: Final answer
    x = 1,363.22

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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.