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Finding the Fourth Proportional to 712.81, 983.69 and 393.78

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Solution

The fourth proportional to 712.81, 983.69 and 393.78 is: 543.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    712.81 : 983.69 = 393.78 : x
  2. Step 2: Convert to fraction form
    712.81/983.69 = 393.78/x
  3. Step 3: Cross multiply
    712.81x = 983.69 × 393.78
  4. Step 4: Simplify right side
    712.81x = 387,357.45
  5. Step 5: Solve for x
    x = 387,357.45/712.81
  6. Step 6: Final answer
    x = 543.42

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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.