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Finding the Fourth Proportional to 1,389.53, 2,084.80 and 649.55

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Solution

The fourth proportional to 1,389.53, 2,084.80 and 649.55 is: 974.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,389.53 : 2,084.80 = 649.55 : x
  2. Step 2: Convert to fraction form
    1,389.53/2,084.80 = 649.55/x
  3. Step 3: Cross multiply
    1,389.53x = 2,084.80 × 649.55
  4. Step 4: Simplify right side
    1,389.53x = 1,354,181.84
  5. Step 5: Solve for x
    x = 1,354,181.84/1,389.53
  6. Step 6: Final answer
    x = 974.56

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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.