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Finding the Fourth Proportional to 639.60, 957.60 and 494.40

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Solution

The fourth proportional to 639.60, 957.60 and 494.40 is: 740.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.60 : 957.60 = 494.40 : x
  2. Step 2: Convert to fraction form
    639.60/957.60 = 494.40/x
  3. Step 3: Cross multiply
    639.60x = 957.60 × 494.40
  4. Step 4: Simplify right side
    639.60x = 473,437.44
  5. Step 5: Solve for x
    x = 473,437.44/639.60
  6. Step 6: Final answer
    x = 740.21

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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.