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Finding the Fourth Proportional to 1,245.70, 1,719.07 and 686.17

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Solution

The fourth proportional to 1,245.70, 1,719.07 and 686.17 is: 946.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,245.70 : 1,719.07 = 686.17 : x
  2. Step 2: Convert to fraction form
    1,245.70/1,719.07 = 686.17/x
  3. Step 3: Cross multiply
    1,245.70x = 1,719.07 × 686.17
  4. Step 4: Simplify right side
    1,245.70x = 1,179,568.25
  5. Step 5: Solve for x
    x = 1,179,568.25/1,245.70
  6. Step 6: Final answer
    x = 946.91

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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.