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Finding the Fourth Proportional to 445.64, 615.18 and 390.44

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Solution

The fourth proportional to 445.64, 615.18 and 390.44 is: 538.98

Step by Step Solution

  1. Step 1: Write the proportion equation
    445.64 : 615.18 = 390.44 : x
  2. Step 2: Convert to fraction form
    445.64/615.18 = 390.44/x
  3. Step 3: Cross multiply
    445.64x = 615.18 × 390.44
  4. Step 4: Simplify right side
    445.64x = 240,190.88
  5. Step 5: Solve for x
    x = 240,190.88/445.64
  6. Step 6: Final answer
    x = 538.98

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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.