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Finding the Fourth Proportional to 938.28, 1,407.21 and 280.14

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Solution

The fourth proportional to 938.28, 1,407.21 and 280.14 is: 420.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    938.28 : 1,407.21 = 280.14 : x
  2. Step 2: Convert to fraction form
    938.28/1,407.21 = 280.14/x
  3. Step 3: Cross multiply
    938.28x = 1,407.21 × 280.14
  4. Step 4: Simplify right side
    938.28x = 394,215.81
  5. Step 5: Solve for x
    x = 394,215.81/938.28
  6. Step 6: Final answer
    x = 420.15

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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.