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Finding the Fourth Proportional to 74.78, 103.10 and 57.30

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Solution

The fourth proportional to 74.78, 103.10 and 57.30 is: 79.00

Step by Step Solution

  1. Step 1: Write the proportion equation
    74.78 : 103.10 = 57.30 : x
  2. Step 2: Convert to fraction form
    74.78/103.10 = 57.30/x
  3. Step 3: Cross multiply
    74.78x = 103.10 × 57.30
  4. Step 4: Simplify right side
    74.78x = 5,907.63
  5. Step 5: Solve for x
    x = 5,907.63/74.78
  6. Step 6: Final answer
    x = 79.00

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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.