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Finding the Fourth Proportional to 388.80, 535.55 and 318.60

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Solution

The fourth proportional to 388.80, 535.55 and 318.60 is: 438.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    388.80 : 535.55 = 318.60 : x
  2. Step 2: Convert to fraction form
    388.80/535.55 = 318.60/x
  3. Step 3: Cross multiply
    388.80x = 535.55 × 318.60
  4. Step 4: Simplify right side
    388.80x = 170,624.64
  5. Step 5: Solve for x
    x = 170,624.64/388.80
  6. Step 6: Final answer
    x = 438.85

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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.