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Finding the Fourth Proportional to 1,388.25, 2,082.65 and 618.75

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Solution

The fourth proportional to 1,388.25, 2,082.65 and 618.75 is: 928.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,388.25 : 2,082.65 = 618.75 : x
  2. Step 2: Convert to fraction form
    1,388.25/2,082.65 = 618.75/x
  3. Step 3: Cross multiply
    1,388.25x = 2,082.65 × 618.75
  4. Step 4: Simplify right side
    1,388.25x = 1,288,636.59
  5. Step 5: Solve for x
    x = 1,288,636.59/1,388.25
  6. Step 6: Final answer
    x = 928.25

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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.