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Finding the Fourth Proportional to 628.68, 867.38 and 421.72

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Solution

The fourth proportional to 628.68, 867.38 and 421.72 is: 581.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    628.68 : 867.38 = 421.72 : x
  2. Step 2: Convert to fraction form
    628.68/867.38 = 421.72/x
  3. Step 3: Cross multiply
    628.68x = 867.38 × 421.72
  4. Step 4: Simplify right side
    628.68x = 365,791.49
  5. Step 5: Solve for x
    x = 365,791.49/628.68
  6. Step 6: Final answer
    x = 581.84

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Double scale
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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.