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Finding the Fourth Proportional to 680.40, 938.18 and 494.51

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Solution

The fourth proportional to 680.40, 938.18 and 494.51 is: 681.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    680.40 : 938.18 = 494.51 : x
  2. Step 2: Convert to fraction form
    680.40/938.18 = 494.51/x
  3. Step 3: Cross multiply
    680.40x = 938.18 × 494.51
  4. Step 4: Simplify right side
    680.40x = 463,935.94
  5. Step 5: Solve for x
    x = 463,935.94/680.40
  6. Step 6: Final answer
    x = 681.86

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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.