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Finding the Fourth Proportional to 645.68, 968.90 and 280.51

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Solution

The fourth proportional to 645.68, 968.90 and 280.51 is: 420.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    645.68 : 968.90 = 280.51 : x
  2. Step 2: Convert to fraction form
    645.68/968.90 = 280.51/x
  3. Step 3: Cross multiply
    645.68x = 968.90 × 280.51
  4. Step 4: Simplify right side
    645.68x = 271,782.31
  5. Step 5: Solve for x
    x = 271,782.31/645.68
  6. Step 6: Final answer
    x = 420.92

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Double scale
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Similar ratio
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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.