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Finding the Fourth Proportional to 645.78, 968.80 and 212.96

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Solution

The fourth proportional to 645.78, 968.80 and 212.96 is: 319.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    645.78 : 968.80 = 212.96 : x
  2. Step 2: Convert to fraction form
    645.78/968.80 = 212.96/x
  3. Step 3: Cross multiply
    645.78x = 968.80 × 212.96
  4. Step 4: Simplify right side
    645.78x = 206,315.65
  5. Step 5: Solve for x
    x = 206,315.65/645.78
  6. Step 6: Final answer
    x = 319.48

Related Problems

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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.