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Finding the Fourth Proportional to 938.30, 1,407.18 and 280.15

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Solution

The fourth proportional to 938.30, 1,407.18 and 280.15 is: 420.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    938.30 : 1,407.18 = 280.15 : x
  2. Step 2: Convert to fraction form
    938.30/1,407.18 = 280.15/x
  3. Step 3: Cross multiply
    938.30x = 1,407.18 × 280.15
  4. Step 4: Simplify right side
    938.30x = 394,221.48
  5. Step 5: Solve for x
    x = 394,221.48/938.30
  6. Step 6: Final answer
    x = 420.14

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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.