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Finding the Fourth Proportional to 641.64, 961.62 and 257.16

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Solution

The fourth proportional to 641.64, 961.62 and 257.16 is: 385.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    641.64 : 961.62 = 257.16 : x
  2. Step 2: Convert to fraction form
    641.64/961.62 = 257.16/x
  3. Step 3: Cross multiply
    641.64x = 961.62 × 257.16
  4. Step 4: Simplify right side
    641.64x = 247,290.20
  5. Step 5: Solve for x
    x = 247,290.20/641.64
  6. Step 6: Final answer
    x = 385.40

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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.