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Finding the Fourth Proportional to 640.87, 959.90 and 393.32

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Solution

The fourth proportional to 640.87, 959.90 and 393.32 is: 589.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    640.87 : 959.90 = 393.32 : x
  2. Step 2: Convert to fraction form
    640.87/959.90 = 393.32/x
  3. Step 3: Cross multiply
    640.87x = 959.90 × 393.32
  4. Step 4: Simplify right side
    640.87x = 377,547.87
  5. Step 5: Solve for x
    x = 377,547.87/640.87
  6. Step 6: Final answer
    x = 589.12

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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.