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Finding the Fourth Proportional to 638, 880.40 and 358.28

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Solution

The fourth proportional to 638, 880.40 and 358.28 is: 494.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    638 : 880.40 = 358.28 : x
  2. Step 2: Convert to fraction form
    638/880.40 = 358.28/x
  3. Step 3: Cross multiply
    638x = 880.40 × 358.28
  4. Step 4: Simplify right side
    638x = 315,429.71
  5. Step 5: Solve for x
    x = 315,429.71/638
  6. Step 6: Final answer
    x = 494.40

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.