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Finding the Fourth Proportional to 1,380.90, 2,071.35 and 649.62

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Solution

The fourth proportional to 1,380.90, 2,071.35 and 649.62 is: 974.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,380.90 : 2,071.35 = 649.62 : x
  2. Step 2: Convert to fraction form
    1,380.90/2,071.35 = 649.62/x
  3. Step 3: Cross multiply
    1,380.90x = 2,071.35 × 649.62
  4. Step 4: Simplify right side
    1,380.90x = 1,345,590.39
  5. Step 5: Solve for x
    x = 1,345,590.39/1,380.90
  6. Step 6: Final answer
    x = 974.43

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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.