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Finding the Fourth Proportional to 431.15, 646.79 and 157.21

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Solution

The fourth proportional to 431.15, 646.79 and 157.21 is: 235.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    431.15 : 646.79 = 157.21 : x
  2. Step 2: Convert to fraction form
    431.15/646.79 = 157.21/x
  3. Step 3: Cross multiply
    431.15x = 646.79 × 157.21
  4. Step 4: Simplify right side
    431.15x = 101,681.86
  5. Step 5: Solve for x
    x = 101,681.86/431.15
  6. Step 6: Final answer
    x = 235.84

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.