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Finding the Fourth Proportional to 628.79, 867.65 and 380.21

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Solution

The fourth proportional to 628.79, 867.65 and 380.21 is: 524.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    628.79 : 867.65 = 380.21 : x
  2. Step 2: Convert to fraction form
    628.79/867.65 = 380.21/x
  3. Step 3: Cross multiply
    628.79x = 867.65 × 380.21
  4. Step 4: Simplify right side
    628.79x = 329,882.97
  5. Step 5: Solve for x
    x = 329,882.97/628.79
  6. Step 6: Final answer
    x = 524.64

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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.