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Finding the Fourth Proportional to 677.40, 1,015.92 and 419.28

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Solution

The fourth proportional to 677.40, 1,015.92 and 419.28 is: 628.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    677.40 : 1,015.92 = 419.28 : x
  2. Step 2: Convert to fraction form
    677.40/1,015.92 = 419.28/x
  3. Step 3: Cross multiply
    677.40x = 1,015.92 × 419.28
  4. Step 4: Simplify right side
    677.40x = 425,954.94
  5. Step 5: Solve for x
    x = 425,954.94/677.40
  6. Step 6: Final answer
    x = 628.81

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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.