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Finding the Fourth Proportional to 628, 866.82 and 421

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Solution

The fourth proportional to 628, 866.82 and 421 is: 581.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    628 : 866.82 = 421 : x
  2. Step 2: Convert to fraction form
    628/866.82 = 421/x
  3. Step 3: Cross multiply
    628x = 866.82 × 421
  4. Step 4: Simplify right side
    628x = 364,931.22
  5. Step 5: Solve for x
    x = 364,931.22/628
  6. Step 6: Final answer
    x = 581.10

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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.