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Finding the Fourth Proportional to 368.78, 508.85 and 221.38

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Solution

The fourth proportional to 368.78, 508.85 and 221.38 is: 305.46

Step by Step Solution

  1. Step 1: Write the proportion equation
    368.78 : 508.85 = 221.38 : x
  2. Step 2: Convert to fraction form
    368.78/508.85 = 221.38/x
  3. Step 3: Cross multiply
    368.78x = 508.85 × 221.38
  4. Step 4: Simplify right side
    368.78x = 112,649.21
  5. Step 5: Solve for x
    x = 112,649.21/368.78
  6. Step 6: Final answer
    x = 305.46

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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.