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Finding the Fourth Proportional to 628.78, 942.40 and 281.72

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Solution

The fourth proportional to 628.78, 942.40 and 281.72 is: 422.24

Step by Step Solution

  1. Step 1: Write the proportion equation
    628.78 : 942.40 = 281.72 : x
  2. Step 2: Convert to fraction form
    628.78/942.40 = 281.72/x
  3. Step 3: Cross multiply
    628.78x = 942.40 × 281.72
  4. Step 4: Simplify right side
    628.78x = 265,492.93
  5. Step 5: Solve for x
    x = 265,492.93/628.78
  6. Step 6: Final answer
    x = 422.24

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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.