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Finding the Fourth Proportional to 855.10, 1,281.30 and 636.40

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Solution

The fourth proportional to 855.10, 1,281.30 and 636.40 is: 953.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    855.10 : 1,281.30 = 636.40 : x
  2. Step 2: Convert to fraction form
    855.10/1,281.30 = 636.40/x
  3. Step 3: Cross multiply
    855.10x = 1,281.30 × 636.40
  4. Step 4: Simplify right side
    855.10x = 815,419.32
  5. Step 5: Solve for x
    x = 815,419.32/855.10
  6. Step 6: Final answer
    x = 953.60

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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.