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Finding the Fourth Proportional to 858.40, 1,286.89 and 395.58

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Solution

The fourth proportional to 858.40, 1,286.89 and 395.58 is: 593.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    858.40 : 1,286.89 = 395.58 : x
  2. Step 2: Convert to fraction form
    858.40/1,286.89 = 395.58/x
  3. Step 3: Cross multiply
    858.40x = 1,286.89 × 395.58
  4. Step 4: Simplify right side
    858.40x = 509,071.78
  5. Step 5: Solve for x
    x = 509,071.78/858.40
  6. Step 6: Final answer
    x = 593.05

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.