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Finding the Fourth Proportional to 305.18, 420.65 and 238.67

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Solution

The fourth proportional to 305.18, 420.65 and 238.67 is: 328.98

Step by Step Solution

  1. Step 1: Write the proportion equation
    305.18 : 420.65 = 238.67 : x
  2. Step 2: Convert to fraction form
    305.18/420.65 = 238.67/x
  3. Step 3: Cross multiply
    305.18x = 420.65 × 238.67
  4. Step 4: Simplify right side
    305.18x = 100,397.57
  5. Step 5: Solve for x
    x = 100,397.57/305.18
  6. Step 6: Final answer
    x = 328.98

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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.