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Finding the Fourth Proportional to 1,389.50, 2,084.53 and 620

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Solution

The fourth proportional to 1,389.50, 2,084.53 and 620 is: 930.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,389.50 : 2,084.53 = 620 : x
  2. Step 2: Convert to fraction form
    1,389.50/2,084.53 = 620/x
  3. Step 3: Cross multiply
    1,389.50x = 2,084.53 × 620
  4. Step 4: Simplify right side
    1,389.50x = 1,292,408.60
  5. Step 5: Solve for x
    x = 1,292,408.60/1,389.50
  6. Step 6: Final answer
    x = 930.12

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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.