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Finding the Fourth Proportional to 1,388.75, 2,082.21 and 657.92

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Solution

The fourth proportional to 1,388.75, 2,082.21 and 657.92 is: 986.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,388.75 : 2,082.21 = 657.92 : x
  2. Step 2: Convert to fraction form
    1,388.75/2,082.21 = 657.92/x
  3. Step 3: Cross multiply
    1,388.75x = 2,082.21 × 657.92
  4. Step 4: Simplify right side
    1,388.75x = 1,369,930.34
  5. Step 5: Solve for x
    x = 1,369,930.34/1,388.75
  6. Step 6: Final answer
    x = 986.45

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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.