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Finding the Fourth Proportional to 641.25, 961.88 and 256.50

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Solution

The fourth proportional to 641.25, 961.88 and 256.50 is: 384.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    641.25 : 961.88 = 256.50 : x
  2. Step 2: Convert to fraction form
    641.25/961.88 = 256.50/x
  3. Step 3: Cross multiply
    641.25x = 961.88 × 256.50
  4. Step 4: Simplify right side
    641.25x = 246,720.94
  5. Step 5: Solve for x
    x = 246,720.94/641.25
  6. Step 6: Final answer
    x = 384.75

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Double scale
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Similar ratio
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1.5x scale

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.