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Finding the Fourth Proportional to 677.64, 1,015.68 and 389.28

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Solution

The fourth proportional to 677.64, 1,015.68 and 389.28 is: 583.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    677.64 : 1,015.68 = 389.28 : x
  2. Step 2: Convert to fraction form
    677.64/1,015.68 = 389.28/x
  3. Step 3: Cross multiply
    677.64x = 1,015.68 × 389.28
  4. Step 4: Simplify right side
    677.64x = 395,383.91
  5. Step 5: Solve for x
    x = 395,383.91/677.64
  6. Step 6: Final answer
    x = 583.47

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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.