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Finding the Fourth Proportional to 85.09, 117.40 and 57.45

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Solution

The fourth proportional to 85.09, 117.40 and 57.45 is: 79.26

Step by Step Solution

  1. Step 1: Write the proportion equation
    85.09 : 117.40 = 57.45 : x
  2. Step 2: Convert to fraction form
    85.09/117.40 = 57.45/x
  3. Step 3: Cross multiply
    85.09x = 117.40 × 57.45
  4. Step 4: Simplify right side
    85.09x = 6,744.63
  5. Step 5: Solve for x
    x = 6,744.63/85.09
  6. Step 6: Final answer
    x = 79.26

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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.