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Finding the Fourth Proportional to 259.74, 388.80 and 205.20

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Solution

The fourth proportional to 259.74, 388.80 and 205.20 is: 307.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    259.74 : 388.80 = 205.20 : x
  2. Step 2: Convert to fraction form
    259.74/388.80 = 205.20/x
  3. Step 3: Cross multiply
    259.74x = 388.80 × 205.20
  4. Step 4: Simplify right side
    259.74x = 79,781.76
  5. Step 5: Solve for x
    x = 79,781.76/259.74
  6. Step 6: Final answer
    x = 307.16

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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.