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Finding the Fourth Proportional to 310.84, 428.09 and 290.18

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Solution

The fourth proportional to 310.84, 428.09 and 290.18 is: 399.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    310.84 : 428.09 = 290.18 : x
  2. Step 2: Convert to fraction form
    310.84/428.09 = 290.18/x
  3. Step 3: Cross multiply
    310.84x = 428.09 × 290.18
  4. Step 4: Simplify right side
    310.84x = 124,222.78
  5. Step 5: Solve for x
    x = 124,222.78/310.84
  6. Step 6: Final answer
    x = 399.64

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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.