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Finding the Fourth Proportional to 680.49, 938.95 and 428.28

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Solution

The fourth proportional to 680.49, 938.95 and 428.28 is: 590.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    680.49 : 938.95 = 428.28 : x
  2. Step 2: Convert to fraction form
    680.49/938.95 = 428.28/x
  3. Step 3: Cross multiply
    680.49x = 938.95 × 428.28
  4. Step 4: Simplify right side
    680.49x = 402,133.51
  5. Step 5: Solve for x
    x = 402,133.51/680.49
  6. Step 6: Final answer
    x = 590.95

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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.