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Finding the Fourth Proportional to 311.39, 432.74 and 307.55

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Solution

The fourth proportional to 311.39, 432.74 and 307.55 is: 427.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    311.39 : 432.74 = 307.55 : x
  2. Step 2: Convert to fraction form
    311.39/432.74 = 307.55/x
  3. Step 3: Cross multiply
    311.39x = 432.74 × 307.55
  4. Step 4: Simplify right side
    311.39x = 133,088.60
  5. Step 5: Solve for x
    x = 133,088.60/311.39
  6. Step 6: Final answer
    x = 427.40

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Why These Related Problems?

These problems maintain the same ratio (1.39) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.