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Finding the Fourth Proportional to 515.18, 772.78 and 258.86

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Solution

The fourth proportional to 515.18, 772.78 and 258.86 is: 388.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    515.18 : 772.78 = 258.86 : x
  2. Step 2: Convert to fraction form
    515.18/772.78 = 258.86/x
  3. Step 3: Cross multiply
    515.18x = 772.78 × 258.86
  4. Step 4: Simplify right side
    515.18x = 200,041.83
  5. Step 5: Solve for x
    x = 200,041.83/515.18
  6. Step 6: Final answer
    x = 388.30

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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.