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Finding the Fourth Proportional to 631.40, 947.09 and 261.11

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Solution

The fourth proportional to 631.40, 947.09 and 261.11 is: 391.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    631.40 : 947.09 = 261.11 : x
  2. Step 2: Convert to fraction form
    631.40/947.09 = 261.11/x
  3. Step 3: Cross multiply
    631.40x = 947.09 × 261.11
  4. Step 4: Simplify right side
    631.40x = 247,297.69
  5. Step 5: Solve for x
    x = 247,297.69/631.40
  6. Step 6: Final answer
    x = 391.67

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Double scale
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Similar ratio
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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.