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Finding the Fourth Proportional to 1,378.43, 2,064.30 and 648.21

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Solution

The fourth proportional to 1,378.43, 2,064.30 and 648.21 is: 970.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,378.43 : 2,064.30 = 648.21 : x
  2. Step 2: Convert to fraction form
    1,378.43/2,064.30 = 648.21/x
  3. Step 3: Cross multiply
    1,378.43x = 2,064.30 × 648.21
  4. Step 4: Simplify right side
    1,378.43x = 1,338,099.90
  5. Step 5: Solve for x
    x = 1,338,099.90/1,378.43
  6. Step 6: Final answer
    x = 970.74

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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.