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Finding the Fourth Proportional to 712.40, 984.29 and 687.42

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Solution

The fourth proportional to 712.40, 984.29 and 687.42 is: 949.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    712.40 : 984.29 = 687.42 : x
  2. Step 2: Convert to fraction form
    712.40/984.29 = 687.42/x
  3. Step 3: Cross multiply
    712.40x = 984.29 × 687.42
  4. Step 4: Simplify right side
    712.40x = 676,617.19
  5. Step 5: Solve for x
    x = 676,617.19/712.40
  6. Step 6: Final answer
    x = 949.78

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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.