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Finding the Fourth Proportional to 940.02, 1,409.72 and 420

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Solution

The fourth proportional to 940.02, 1,409.72 and 420 is: 629.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    940.02 : 1,409.72 = 420 : x
  2. Step 2: Convert to fraction form
    940.02/1,409.72 = 420/x
  3. Step 3: Cross multiply
    940.02x = 1,409.72 × 420
  4. Step 4: Simplify right side
    940.02x = 592,082.40
  5. Step 5: Solve for x
    x = 592,082.40/940.02
  6. Step 6: Final answer
    x = 629.86

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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.