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Finding the Fourth Proportional to 228.72, 342.40 and 215.40

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Solution

The fourth proportional to 228.72, 342.40 and 215.40 is: 322.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    228.72 : 342.40 = 215.40 : x
  2. Step 2: Convert to fraction form
    228.72/342.40 = 215.40/x
  3. Step 3: Cross multiply
    228.72x = 342.40 × 215.40
  4. Step 4: Simplify right side
    228.72x = 73,752.31
  5. Step 5: Solve for x
    x = 73,752.31/228.72
  6. Step 6: Final answer
    x = 322.45

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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.