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Finding the Fourth Proportional to 391, 539.58 and 235.78

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Solution

The fourth proportional to 391, 539.58 and 235.78 is: 325.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    391 : 539.58 = 235.78 : x
  2. Step 2: Convert to fraction form
    391/539.58 = 235.78/x
  3. Step 3: Cross multiply
    391x = 539.58 × 235.78
  4. Step 4: Simplify right side
    391x = 127,222.17
  5. Step 5: Solve for x
    x = 127,222.17/391
  6. Step 6: Final answer
    x = 325.38

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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.