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Finding the Fourth Proportional to 615.12, 847.98 and 393.90

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Solution

The fourth proportional to 615.12, 847.98 and 393.90 is: 543.01

Step by Step Solution

  1. Step 1: Write the proportion equation
    615.12 : 847.98 = 393.90 : x
  2. Step 2: Convert to fraction form
    615.12/847.98 = 393.90/x
  3. Step 3: Cross multiply
    615.12x = 847.98 × 393.90
  4. Step 4: Simplify right side
    615.12x = 334,019.32
  5. Step 5: Solve for x
    x = 334,019.32/615.12
  6. Step 6: Final answer
    x = 543.01

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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.