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Finding the Fourth Proportional to 1,388.70, 2,079.45 and 1,098.30

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Solution

The fourth proportional to 1,388.70, 2,079.45 and 1,098.30 is: 1,644.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,388.70 : 2,079.45 = 1,098.30 : x
  2. Step 2: Convert to fraction form
    1,388.70/2,079.45 = 1,098.30/x
  3. Step 3: Cross multiply
    1,388.70x = 2,079.45 × 1,098.30
  4. Step 4: Simplify right side
    1,388.70x = 2,283,859.94
  5. Step 5: Solve for x
    x = 2,283,859.94/1,388.70
  6. Step 6: Final answer
    x = 1,644.60

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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.