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Finding the Fourth Proportional to 688.12, 1,032.36 and 399.28

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Solution

The fourth proportional to 688.12, 1,032.36 and 399.28 is: 599.02

Step by Step Solution

  1. Step 1: Write the proportion equation
    688.12 : 1,032.36 = 399.28 : x
  2. Step 2: Convert to fraction form
    688.12/1,032.36 = 399.28/x
  3. Step 3: Cross multiply
    688.12x = 1,032.36 × 399.28
  4. Step 4: Simplify right side
    688.12x = 412,200.70
  5. Step 5: Solve for x
    x = 412,200.70/688.12
  6. Step 6: Final answer
    x = 599.02

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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.