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Finding the Fourth Proportional to 319.70, 440.78 and 209.00

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Solution

The fourth proportional to 319.70, 440.78 and 209.00 is: 288.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    319.70 : 440.78 = 209.00 : x
  2. Step 2: Convert to fraction form
    319.70/440.78 = 209.00/x
  3. Step 3: Cross multiply
    319.70x = 440.78 × 209.00
  4. Step 4: Simplify right side
    319.70x = 92,122.60
  5. Step 5: Solve for x
    x = 92,122.60/319.70
  6. Step 6: Final answer
    x = 288.15

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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.