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Finding the Fourth Proportional to 310.40, 427.56 and 257.84

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Solution

The fourth proportional to 310.40, 427.56 and 257.84 is: 355.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    310.40 : 427.56 = 257.84 : x
  2. Step 2: Convert to fraction form
    310.40/427.56 = 257.84/x
  3. Step 3: Cross multiply
    310.40x = 427.56 × 257.84
  4. Step 4: Simplify right side
    310.40x = 110,242.07
  5. Step 5: Solve for x
    x = 110,242.07/310.40
  6. Step 6: Final answer
    x = 355.16

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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.