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Finding the Fourth Proportional to 665.39, 919.35 and 478.50

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Solution

The fourth proportional to 665.39, 919.35 and 478.50 is: 661.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    665.39 : 919.35 = 478.50 : x
  2. Step 2: Convert to fraction form
    665.39/919.35 = 478.50/x
  3. Step 3: Cross multiply
    665.39x = 919.35 × 478.50
  4. Step 4: Simplify right side
    665.39x = 439,910.70
  5. Step 5: Solve for x
    x = 439,910.70/665.39
  6. Step 6: Final answer
    x = 661.14

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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.