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Finding the Fourth Proportional to 1,021.71, 1,409.86 and 628.72

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Solution

The fourth proportional to 1,021.71, 1,409.86 and 628.72 is: 867.57

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,021.71 : 1,409.86 = 628.72 : x
  2. Step 2: Convert to fraction form
    1,021.71/1,409.86 = 628.72/x
  3. Step 3: Cross multiply
    1,021.71x = 1,409.86 × 628.72
  4. Step 4: Simplify right side
    1,021.71x = 886,407.18
  5. Step 5: Solve for x
    x = 886,407.18/1,021.71
  6. Step 6: Final answer
    x = 867.57

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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.