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Finding the Fourth Proportional to 310.67, 428.79 and 186.40

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Solution

The fourth proportional to 310.67, 428.79 and 186.40 is: 257.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    310.67 : 428.79 = 186.40 : x
  2. Step 2: Convert to fraction form
    310.67/428.79 = 186.40/x
  3. Step 3: Cross multiply
    310.67x = 428.79 × 186.40
  4. Step 4: Simplify right side
    310.67x = 79,927.69
  5. Step 5: Solve for x
    x = 79,927.69/310.67
  6. Step 6: Final answer
    x = 257.28

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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.