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Finding the Fourth Proportional to 310.87, 428.80 and 186.45

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Solution

The fourth proportional to 310.87, 428.80 and 186.45 is: 257.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    310.87 : 428.80 = 186.45 : x
  2. Step 2: Convert to fraction form
    310.87/428.80 = 186.45/x
  3. Step 3: Cross multiply
    310.87x = 428.80 × 186.45
  4. Step 4: Simplify right side
    310.87x = 79,949.76
  5. Step 5: Solve for x
    x = 79,949.76/310.87
  6. Step 6: Final answer
    x = 257.18

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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.