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Finding the Fourth Proportional to 280.74, 387.60 and 215.12

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Solution

The fourth proportional to 280.74, 387.60 and 215.12 is: 297.00

Step by Step Solution

  1. Step 1: Write the proportion equation
    280.74 : 387.60 = 215.12 : x
  2. Step 2: Convert to fraction form
    280.74/387.60 = 215.12/x
  3. Step 3: Cross multiply
    280.74x = 387.60 × 215.12
  4. Step 4: Simplify right side
    280.74x = 83,380.51
  5. Step 5: Solve for x
    x = 83,380.51/280.74
  6. Step 6: Final answer
    x = 297.00

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.