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Finding the Fourth Proportional to 1,389, 2,084.32 and 619.50

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Solution

The fourth proportional to 1,389, 2,084.32 and 619.50 is: 929.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,389 : 2,084.32 = 619.50 : x
  2. Step 2: Convert to fraction form
    1,389/2,084.32 = 619.50/x
  3. Step 3: Cross multiply
    1,389x = 2,084.32 × 619.50
  4. Step 4: Simplify right side
    1,389x = 1,291,236.24
  5. Step 5: Solve for x
    x = 1,291,236.24/1,389
  6. Step 6: Final answer
    x = 929.62

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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.