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Finding the Fourth Proportional to 912.20, 1,258.80 and 519.20

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Solution

The fourth proportional to 912.20, 1,258.80 and 519.20 is: 716.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    912.20 : 1,258.80 = 519.20 : x
  2. Step 2: Convert to fraction form
    912.20/1,258.80 = 519.20/x
  3. Step 3: Cross multiply
    912.20x = 1,258.80 × 519.20
  4. Step 4: Simplify right side
    912.20x = 653,568.96
  5. Step 5: Solve for x
    x = 653,568.96/912.20
  6. Step 6: Final answer
    x = 716.48

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.