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Finding the Fourth Proportional to 1,388, 2,082.28 and 618.50

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Solution

The fourth proportional to 1,388, 2,082.28 and 618.50 is: 927.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,388 : 2,082.28 = 618.50 : x
  2. Step 2: Convert to fraction form
    1,388/2,082.28 = 618.50/x
  3. Step 3: Cross multiply
    1,388x = 2,082.28 × 618.50
  4. Step 4: Simplify right side
    1,388x = 1,287,890.18
  5. Step 5: Solve for x
    x = 1,287,890.18/1,388
  6. Step 6: Final answer
    x = 927.87

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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.