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Finding the Fourth Proportional to 615.36, 920.64 and 422.40

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Solution

The fourth proportional to 615.36, 920.64 and 422.40 is: 631.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    615.36 : 920.64 = 422.40 : x
  2. Step 2: Convert to fraction form
    615.36/920.64 = 422.40/x
  3. Step 3: Cross multiply
    615.36x = 920.64 × 422.40
  4. Step 4: Simplify right side
    615.36x = 388,878.34
  5. Step 5: Solve for x
    x = 388,878.34/615.36
  6. Step 6: Final answer
    x = 631.95

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.