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Finding the Fourth Proportional to 681.60, 938.66 and 667.20

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Solution

The fourth proportional to 681.60, 938.66 and 667.20 is: 918.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    681.60 : 938.66 = 667.20 : x
  2. Step 2: Convert to fraction form
    681.60/938.66 = 667.20/x
  3. Step 3: Cross multiply
    681.60x = 938.66 × 667.20
  4. Step 4: Simplify right side
    681.60x = 626,273.95
  5. Step 5: Solve for x
    x = 626,273.95/681.60
  6. Step 6: Final answer
    x = 918.83

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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.