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Finding the Fourth Proportional to 1,325.12, 1,985.12 and 641.60

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Solution

The fourth proportional to 1,325.12, 1,985.12 and 641.60 is: 961.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,325.12 : 1,985.12 = 641.60 : x
  2. Step 2: Convert to fraction form
    1,325.12/1,985.12 = 641.60/x
  3. Step 3: Cross multiply
    1,325.12x = 1,985.12 × 641.60
  4. Step 4: Simplify right side
    1,325.12x = 1,273,652.99
  5. Step 5: Solve for x
    x = 1,273,652.99/1,325.12
  6. Step 6: Final answer
    x = 961.16

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1.5x scale

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.