Home / 1,021.71-1,531.70-405.85

Finding the Fourth Proportional to 1,021.71, 1,531.70 and 405.85

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Solution

The fourth proportional to 1,021.71, 1,531.70 and 405.85 is: 608.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,021.71 : 1,531.70 = 405.85 : x
  2. Step 2: Convert to fraction form
    1,021.71/1,531.70 = 405.85/x
  3. Step 3: Cross multiply
    1,021.71x = 1,531.70 × 405.85
  4. Step 4: Simplify right side
    1,021.71x = 621,640.45
  5. Step 5: Solve for x
    x = 621,640.45/1,021.71
  6. Step 6: Final answer
    x = 608.43

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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.