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Finding the Fourth Proportional to 857.79, 1,284.96 and 394.94

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Solution

The fourth proportional to 857.79, 1,284.96 and 394.94 is: 591.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    857.79 : 1,284.96 = 394.94 : x
  2. Step 2: Convert to fraction form
    857.79/1,284.96 = 394.94/x
  3. Step 3: Cross multiply
    857.79x = 1,284.96 × 394.94
  4. Step 4: Simplify right side
    857.79x = 507,486.80
  5. Step 5: Solve for x
    x = 507,486.80/857.79
  6. Step 6: Final answer
    x = 591.62

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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.