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Finding the Fourth Proportional to 388.40, 581.40 and 306.80

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Solution

The fourth proportional to 388.40, 581.40 and 306.80 is: 459.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    388.40 : 581.40 = 306.80 : x
  2. Step 2: Convert to fraction form
    388.40/581.40 = 306.80/x
  3. Step 3: Cross multiply
    388.40x = 581.40 × 306.80
  4. Step 4: Simplify right side
    388.40x = 178,373.52
  5. Step 5: Solve for x
    x = 178,373.52/388.40
  6. Step 6: Final answer
    x = 459.25

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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.