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Finding the Fourth Proportional to 857.40, 1,284.90 and 636.30

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Solution

The fourth proportional to 857.40, 1,284.90 and 636.30 is: 953.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    857.40 : 1,284.90 = 636.30 : x
  2. Step 2: Convert to fraction form
    857.40/1,284.90 = 636.30/x
  3. Step 3: Cross multiply
    857.40x = 1,284.90 × 636.30
  4. Step 4: Simplify right side
    857.40x = 817,581.87
  5. Step 5: Solve for x
    x = 817,581.87/857.40
  6. Step 6: Final answer
    x = 953.56

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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.