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Finding the Fourth Proportional to 371.78, 511.88 and 305.51

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Solution

The fourth proportional to 371.78, 511.88 and 305.51 is: 420.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    371.78 : 511.88 = 305.51 : x
  2. Step 2: Convert to fraction form
    371.78/511.88 = 305.51/x
  3. Step 3: Cross multiply
    371.78x = 511.88 × 305.51
  4. Step 4: Simplify right side
    371.78x = 156,382.93
  5. Step 5: Solve for x
    x = 156,382.93/371.78
  6. Step 6: Final answer
    x = 420.63

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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.