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Finding the Fourth Proportional to 642.89, 964.61 and 615.21

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Solution

The fourth proportional to 642.89, 964.61 and 615.21 is: 923.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    642.89 : 964.61 = 615.21 : x
  2. Step 2: Convert to fraction form
    642.89/964.61 = 615.21/x
  3. Step 3: Cross multiply
    642.89x = 964.61 × 615.21
  4. Step 4: Simplify right side
    642.89x = 593,432.90
  5. Step 5: Solve for x
    x = 593,432.90/642.89
  6. Step 6: Final answer
    x = 923.08

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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.