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Finding the Fourth Proportional to 680.95, 939.84 and 386.21

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Solution

The fourth proportional to 680.95, 939.84 and 386.21 is: 533.04

Step by Step Solution

  1. Step 1: Write the proportion equation
    680.95 : 939.84 = 386.21 : x
  2. Step 2: Convert to fraction form
    680.95/939.84 = 386.21/x
  3. Step 3: Cross multiply
    680.95x = 939.84 × 386.21
  4. Step 4: Simplify right side
    680.95x = 362,975.61
  5. Step 5: Solve for x
    x = 362,975.61/680.95
  6. Step 6: Final answer
    x = 533.04

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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.