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Finding the Fourth Proportional to 712.91, 983.78 and 398.19

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Solution

The fourth proportional to 712.91, 983.78 and 398.19 is: 549.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    712.91 : 983.78 = 398.19 : x
  2. Step 2: Convert to fraction form
    712.91/983.78 = 398.19/x
  3. Step 3: Cross multiply
    712.91x = 983.78 × 398.19
  4. Step 4: Simplify right side
    712.91x = 391,731.36
  5. Step 5: Solve for x
    x = 391,731.36/712.91
  6. Step 6: Final answer
    x = 549.48

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Double scale
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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.