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Finding the Fourth Proportional to 420.15, 629.75 and 188.76

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Solution

The fourth proportional to 420.15, 629.75 and 188.76 is: 282.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.15 : 629.75 = 188.76 : x
  2. Step 2: Convert to fraction form
    420.15/629.75 = 188.76/x
  3. Step 3: Cross multiply
    420.15x = 629.75 × 188.76
  4. Step 4: Simplify right side
    420.15x = 118,870.67
  5. Step 5: Solve for x
    x = 118,870.67/420.15
  6. Step 6: Final answer
    x = 282.92

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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.