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Finding the Fourth Proportional to 858.25, 1,287.38 and 394.63

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Solution

The fourth proportional to 858.25, 1,287.38 and 394.63 is: 591.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    858.25 : 1,287.38 = 394.63 : x
  2. Step 2: Convert to fraction form
    858.25/1,287.38 = 394.63/x
  3. Step 3: Cross multiply
    858.25x = 1,287.38 × 394.63
  4. Step 4: Simplify right side
    858.25x = 508,036.80
  5. Step 5: Solve for x
    x = 508,036.80/858.25
  6. Step 6: Final answer
    x = 591.95

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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.