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Finding the Fourth Proportional to 228.40, 315.20 and 135.20

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Solution

The fourth proportional to 228.40, 315.20 and 135.20 is: 186.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    228.40 : 315.20 = 135.20 : x
  2. Step 2: Convert to fraction form
    228.40/315.20 = 135.20/x
  3. Step 3: Cross multiply
    228.40x = 315.20 × 135.20
  4. Step 4: Simplify right side
    228.40x = 42,615.04
  5. Step 5: Solve for x
    x = 42,615.04/228.40
  6. Step 6: Final answer
    x = 186.58

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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.