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Finding the Fourth Proportional to 677.48, 1,015.65 and 287.78

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Solution

The fourth proportional to 677.48, 1,015.65 and 287.78 is: 431.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    677.48 : 1,015.65 = 287.78 : x
  2. Step 2: Convert to fraction form
    677.48/1,015.65 = 287.78/x
  3. Step 3: Cross multiply
    677.48x = 1,015.65 × 287.78
  4. Step 4: Simplify right side
    677.48x = 292,278.68
  5. Step 5: Solve for x
    x = 292,278.68/677.48
  6. Step 6: Final answer
    x = 431.42

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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.