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Finding the Fourth Proportional to 107.21, 147.86 and 90.65

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Solution

The fourth proportional to 107.21, 147.86 and 90.65 is: 125.02

Step by Step Solution

  1. Step 1: Write the proportion equation
    107.21 : 147.86 = 90.65 : x
  2. Step 2: Convert to fraction form
    107.21/147.86 = 90.65/x
  3. Step 3: Cross multiply
    107.21x = 147.86 × 90.65
  4. Step 4: Simplify right side
    107.21x = 13,403.51
  5. Step 5: Solve for x
    x = 13,403.51/107.21
  6. Step 6: Final answer
    x = 125.02

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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.