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Finding the Fourth Proportional to 45.90, 68.50 and 39.15

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Solution

The fourth proportional to 45.90, 68.50 and 39.15 is: 58.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    45.90 : 68.50 = 39.15 : x
  2. Step 2: Convert to fraction form
    45.90/68.50 = 39.15/x
  3. Step 3: Cross multiply
    45.90x = 68.50 × 39.15
  4. Step 4: Simplify right side
    45.90x = 2,681.60
  5. Step 5: Solve for x
    x = 2,681.60/45.90
  6. Step 6: Final answer
    x = 58.42

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.