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Finding the Fourth Proportional to 643.64, 965.61 and 210.78

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Solution

The fourth proportional to 643.64, 965.61 and 210.78 is: 316.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.64 : 965.61 = 210.78 : x
  2. Step 2: Convert to fraction form
    643.64/965.61 = 210.78/x
  3. Step 3: Cross multiply
    643.64x = 965.61 × 210.78
  4. Step 4: Simplify right side
    643.64x = 203,531.28
  5. Step 5: Solve for x
    x = 203,531.28/643.64
  6. Step 6: Final answer
    x = 316.22

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Double scale
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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.