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Finding the Fourth Proportional to 423.09, 631.40 and 420.66

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Solution

The fourth proportional to 423.09, 631.40 and 420.66 is: 627.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    423.09 : 631.40 = 420.66 : x
  2. Step 2: Convert to fraction form
    423.09/631.40 = 420.66/x
  3. Step 3: Cross multiply
    423.09x = 631.40 × 420.66
  4. Step 4: Simplify right side
    423.09x = 265,602.62
  5. Step 5: Solve for x
    x = 265,602.62/423.09
  6. Step 6: Final answer
    x = 627.77

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.