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Finding the Fourth Proportional to 712.99, 983.71 and 398.21

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Solution

The fourth proportional to 712.99, 983.71 and 398.21 is: 549.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    712.99 : 983.71 = 398.21 : x
  2. Step 2: Convert to fraction form
    712.99/983.71 = 398.21/x
  3. Step 3: Cross multiply
    712.99x = 983.71 × 398.21
  4. Step 4: Simplify right side
    712.99x = 391,723.98
  5. Step 5: Solve for x
    x = 391,723.98/712.99
  6. Step 6: Final answer
    x = 549.41

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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.