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Finding the Fourth Proportional to 650.40, 975.60 and 639.60

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Solution

The fourth proportional to 650.40, 975.60 and 639.60 is: 959.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    650.40 : 975.60 = 639.60 : x
  2. Step 2: Convert to fraction form
    650.40/975.60 = 639.60/x
  3. Step 3: Cross multiply
    650.40x = 975.60 × 639.60
  4. Step 4: Simplify right side
    650.40x = 623,993.76
  5. Step 5: Solve for x
    x = 623,993.76/650.40
  6. Step 6: Final answer
    x = 959.40

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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.