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Finding the Fourth Proportional to 631.60, 947.40 and 198.80

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Solution

The fourth proportional to 631.60, 947.40 and 198.80 is: 298.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    631.60 : 947.40 = 198.80 : x
  2. Step 2: Convert to fraction form
    631.60/947.40 = 198.80/x
  3. Step 3: Cross multiply
    631.60x = 947.40 × 198.80
  4. Step 4: Simplify right side
    631.60x = 188,343.12
  5. Step 5: Solve for x
    x = 188,343.12/631.60
  6. Step 6: Final answer
    x = 298.20

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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.